Is mascara made out of BAT poop?


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Have you ever heard that there is bat poop in mascara? 😱

It kinda makes sense right? Guano is a valuable fertilizer and is highly sought-after. But is it beneficial to put it on your face?

So, this post came to life when my previous co-worker mentioned that her teacher told her that mascara was made from cow stomach. It honestly didn’t surprise me…you’d be shocked to see what ingredients are found in the products we use each day.

However, I decided to do a little more research…

While I didn’t find anything about cow stomach being used in makeup, I did find claims of guano being a common ingredient. In other words, bat poop in mascara.

Let’s explore this a bit more…

💡TIP: Pin this article to your MAKEUP board so you can always reference it when you need to!

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Let’s Start With Some Fun Facts About Bats.

👉🏼 Bats are actually flying mammals that can maneuver better than birds… thanks to their highly articulated wings. They are commonly mistaken for rodents.

👉🏼 Most cultures in the world associate them with death, witchcraft, vampires, and darkness.

👉🏼 Bats make up 20% of the mammal species; there are over 1200 species of the bat around the world.

👉🏼 Three different species of bats feed on blood. However, most feed on insects and/or fruit.

👉🏼 They “see” in the dark using “echolocation.” Basically, they make high-frequency calls while flying, listen to the echoes returned, and can see a sonic map of their surroundings.

So Then What Is Guano?

Guano is the official word for bat poop (or it can also refer to the poop of a seabird).

Guano is used as a very effective fertilizer around the world. Rich in bioremediation microbes and nitrogen, it contributes to strong plant growth, soil building, and the cleansing of toxins from the soil.

In the ancient Inca civilization, it was even used as a form of currency, since its ownership was quite the privilege.

Last but not least, guano was used in various wars, including the US Civil War since nitrogen can be extracted from guano to make explosives.

Sounds like a miracle product, right? However, this valuable fertilizer comes with a hefty price tag…

Harvesting guano from bat caves significantly impacts bat colonies around the world.

If harvested while the bats are roosting, they’ll typically abandon the caves, leaving their young behind. The explosives used to harvest guano changes the microclimate of the cave and allows light in the cave, making it undesirable for bats to stay.

Additionally, guano also contains dangerous pathogens that lead to histoplasmosis, a dangerous lung infection that affects humans and other animals.

It is commonly misconceived that you can get rabies from bat poop. However, the CDC website debunks that myth, stating that you must be bitten to contract rabies. That’s one good thing, right?

So Is There Really Bat Poop In Mascara?

With all the fabulous things that guano does, what is the benefit of putting it in mascara… or even other makeup products?

There is none.

The good news is that the whole bat poop in mascara thing is really just a massive urban legend.

While I can’t confirm that mascara has never contained bat droppings, I do believe that it’s just a misconception of the word “guanine.”

Once upon a time, guanine was added to various cosmetics to give them a shimmery, iridescent look.

Here’s the thing…guanine is very abundant in bat poop. Heck…the word, “guanine” originates from the word, “guano.” However, the cosmetic industry does not harvest it from bat guano.

sooooo… There isn’t any Bat Guano in makeup?

The FDA requires that guanine only be derived from fish scales when used in beauty products.

If you’re still worried about using fish scales, don’t be… most cosmetic companies aren’t willing to pay the high price for guanine these days.

There are several cheaper alternatives like synthetic pearl, mica, aluminum, and bronze particles.

What Is Mascara Made From?

Mascara is usually made from wax, oils, pigment, and preservatives.

According to WebMD, “Mascara’s ingredients typically include a carbon black or iron oxide pigment to darken lashes; a polymer to form a film that coats lashes; a preservative; and thickening waxes or oils such as lanolin, mineral oil, paraffin, petrolatum, castor oil, carnauba wax, and candelilla wax.”

Lancome Monsieur Big Volume Mascara Too Faced Better Than Sex Mascara Benefit They’re Real! Mascara Buxom Lash Volumizing Mascara Tarte Cosmetics Lights Camera Lashes 4-in-1 Natural Mascara Clinique High Impact Mascara

General FAQ

Why Is Bat Poop In Mascara?

Actually, bat poop is not used in makeup. It’s an urban legend that likely originated because of “guanine,” an ingredient used in various cosmetic products. Although guanine is abundant in bat guano, the FDA requires it to be harvested from fish scales.

What Is The Main Ingredient In Mascara?

Mascara is typically made of wax, oils, pigments, and preservatives.

What Mascaras Have Bat Poop In Them?

None. It’s an urban legend that bat poop is used as a makeup ingredient.

Is Mascara Made of Bat Poop?

No. Mascara does not have bat poop listed as an ingredient. This urban legend likely comes from the fact that “guanine” is used in some beauty products.

Final Thoughts

Although you may have heard that there is bat guano in mascara, that’s really just a wide-spread urban legend.

Some beauty products contain guanine, which is found in bat poop and sounds like guano. However, the FDA requires cosmetic companies to harvest it from fish-scales. Fish scales are pretty gross too… but it’s likely that your mascara doesn’t even use guanine.

So sleep easy, my friend… there is no bat poop in mascara.

Until next time,

Your Turn: Would you be surprised if there was really bat poop in mascara? Are you scared to know what’s in your makeup products? Drop your thoughts in the comments section below! 👇🏼👇🏼👇🏼


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The urban legend about bat guano and mascara is one of many rumors that have circulated over the years about cosmetics, all with varying degrees of truth. They most likely come from a general anxiety that many consumers have about beauty products, with their complicated lists of ingredients and manufacturers who are highly protective of their formulas and processes. The use of animal products as well as the practice of testing cosmetics on animals, sometimes with harsh and painful consequences for them, is also a source of controversy that contributes to rumors about the cosmetics industry. In many cases, it is difficult to find hard evidence that supports assertions like the one that mascara contains bat feces, yet the stories persist.

It appears that some cosmetic companies and salespeople have adapted the rumor about bat guano and mascara to suit their own purposes. Many discussion posts on the Internet can be found that describe salespeople telling stories about other competitors using guano to make mascara, but assuring potential customers that their product does not contain this ingredient. One good way to ease concerns that a person may have about the ingredients in a particular cosmetic or beauty product is to consult a dermatologist or a licensed cosmetologist. They often have knowledge of any possible health effects that may result from compounds used in these types of products.

Although there is no connection between guano and mascara, bat feces has been used, like other forms of excrement, as fertilizer. It is very rich in nitrogen, one of the most important components in fertile soil. Bat guano is also often used by organic gardeners. They prefer it because bats eat only fruit and insects, while other livestock animals whose manure is often used as fertilizer may be fed diets containing hormones, antibiotics, and other substances that may make their way into the excrement.

Just a reminder…Gardening can be a dirty business! We recommend using gardening gloves and washing your hands afterwards. Use with adult supervision and store in a dry area away from kids and pets.

  1. Apply Whitney Farms® Organic Bat Guano
  2. Mix into soil
  3. Water

How much to apply

Type Amount Frequency
Vegetables, annual flowers, and perennials New planting 1/2 cup in bottom of hole. Surface application: 1 1/3 tbsp. per sq. ft. (1 ft. x 1 ft.) HINT: For larger areas, apply 1/3 cup per 4 sq. ft. (2 ft. x 2 ft.) or 4 cups per 50 sq. ft. (5 ft. x 10 ft.) Feed at planting and reapply in 6 weeks. Once blooms have begun to form, switch to Whitney Farms(R) Organic & Natural Tomato & Vegetable Food.
Roses, trees, and shrubs New roses & shrubs: 2 cups per 16 sq. ft. area for new plantings. New trees: 1 to 2 cups in the planting hole plus 1 cup per 3 ft. of height. Established roses, trees, and shrubs: 1 cup for every 2 ft. of height. Feed in Spring after first growth begins. When blossoms form, switch to Whitney Farms(R) Organic & Natural Rose & Flower Food.
Container plants 1 tbsp. per gal. of soil in pot. Hint A standard 6 in. pot holds 1/2 gal., a 12 in. pot holds 3 1/2 gal. Apply every 6 weeks during intial growth phase, then switch to Whitney Farms(R) Organic & Natural All Purpose Plant Food.

How to mix

For new plantings: Work plant food into the garden bed at a depth of 6 to 8 in. by digging or tilling. For larger plants and shrubs, mix fertilizer into soil around root ball.

For established plants: Carefully work fertilizer in the soil around the plant. Avoid piling fertilizer against the stem or trunk.


Containers: When choosing a container, pick one that has a drainage hole. Find a clear or matching saucer to catch any excess water.

For success: Regular feeding promotes big, strong plants with colorful blooms and bountiful harvests.

Don’t overfeed. Overfeeding can be as harmful as underfeeding. Feeding too much can cause weak growth to become susceptible to pests and diseases. Different plants have different plant food needs – find out what your plant prefers and keep a regular schedule.

Harvesting: As a guano product, we recommend a harvest interval when this product is used with edible plants. For root crops, apply the product early and wait 4 months to harvest. For other plants that edible portions are above ground, such as tomatoes, wait at least 3 months to harvest. Always make sure to thoroughly wash edibles before you enjoy them!


This is not the product label. Always read and follow the product label before use.

Bat Guano: The Cannabis Superfood Rich In Macro And Micronutrients


Bats are very social creatures. These adorable little mammals form large colonies that share the same cave for generation after generation. Over the centuries, dunes of excrement build up on the floor of the roost cave, becoming compost. What results is guano, called “wanu” by the ancient South American Quechuans.

Guano is a plant superfood that is rich in the three essential plant nutrients, nitrogen, phosphorus, and potassium. Nitrogen ensures vigorous and verdant growth during the vegetative cycle. Phosphorus supports healthy flowering and root growth. Potassium ensures sturdy trunks and branches. Guano also contains a complete range of micronutrients for overall healthy plant development.

The diet of the particular bat species can alter the nutrient profile of the guano. Insect-eating bats produce a guano that has a high nitrogen content. This makes it ideal for fertilising during the vegetative phase. Fruit-eating bats produce a guano that has a high phosphorus content. This is best for use during the flowering phase when cannabis has a higher demand for phosphorus.

Guano is ideal as an organic soil amendment, either dug-in around the plant or watered-in as a tea. It makes an ideal backbone to any soil recipe, and has the unique characteristic of never burning plants, unlike most nutrients. Fruits and vegetables grown with guano are more flavoursome and resistant to disease. It is the same with cannabis. Guano will “mango” or sweeten the bouquet and flavour of buds when dry.



Use guano as part of an organic soil mix from the start. Along with bone meal, chicken manure, feather meal, and rock dust, guano provides a broad spectrum of essential nutrients, vitamins, and minerals for the cannabis plant. Try this recipe for bountiful cannabis growth.


Probably the most convenient way of adding guano to your garden. Here’s a recipe:

  1. Use 1 tablespoon of guano per litre of water
  2. Use warm water, not hot! You will kill the microorganisms
  3. Stir the water as you add the guano
  4. Leave to rest overnight
  5. Use once per week to guarantee lush growth

Add guano to the soil for a boost in plant performance. Here’s how:

  1. Dig it in (under the mulch) so that it activates properly
  2. It will dry, clump, and not work as effectively if only sprinkled on the surface
  3. Water-in well

The savvy contemporary cannabis consumer is learning to demand high-quality, organic marijuana. Guano is one way of achieving world-class quality when growing organically indoors or outdoors.

The benefits of guano for plant growth are numerous:

  • It improves soil texture. If the soil is too loose, guano will bind it better and increase water retention. If the soil is too dense, guano will loosen the texture and let water penetrate more efficiently.
  • Bioremediation. Guano can help flush toxic elements from the soil while protecting the roots microbially and continuing to feed the affected plant.
  • It encourages healthy decomposition of exhausted material. Adding guano to compost speeds up the composting process and improves friability.
  • It is a slow-release fertiliser. Guano will provide nutrients for most of the life of your plant.
  • It is a pH-adjuster, buffering the pH of the root system.
  • It controls nematodes and is a natural fungicide against chitin (from insect shells).
  • It keeps soil friable and acts as a soil conditioner. Guano adds beneficial enzymes and microflora for continuous soil health.
  • When combined with other additives like worm castings and various meals, guano helps create thriving colonies of root fauna.
  • Used as a dilute spray, guano can help provide plants with fungal protection.


Guano has a long and interesting history as one of the most prized fertilisers in the world. Since well before the arrival of Europeans, guano was a revered fertiliser by the Incas and older South American cultures. It was so important that Incan rulers divided the guano-bearing islands among the provinces. How much could be mined and when were strictly regulated.

Between 1806 and 1841, guano caused astonishment and trepidation in European and new-American farmers. This horticultural curiosity caused such huge and healthy plant growth that it was feared the soil may be depleted irreparably. Within a few years though, it was in great demand by every farmer in the world.

Two million tonnes were imported by Britain from 1840 onwards, and the government of the United States made it a matter of agricultural necessity. During his tenure, President Fillmore said “Guano has become so desirable an article to agricultural interests in the US that it is the duty of the Government to employ all means properly in its power for the purpose of causing this article to be imported into the country at a reasonable price”.

Massive fortunes have been won and lost over the centuries from guano mines. In the mid to late-nineteenth century, it caused a mania not unlike the California gold rush. Over a forty-year period, Peru exported over twenty million tonnes of guano around the world for a profit of two billion dollars.

Rich in essential macro and micronutrients, bat guano is an organic superfood that will delight the contemporary cannabis grower. For naturally flourishing plants, guano is an unbeatable addition to any organic grow, both indoors or outdoors.

How To Use Bat Guano As A Fertilizer

Bat guano, or feces, has a long history of use as a soil enricher. It is obtained from only fruit and insect-feeding species. Bat dung makes an excellent fertilizer. It’s fast-acting, has little odor, and can be worked into the soil prior to planting or during active growth. Let’s learn more about how to use bat guano as a fertilizer.

What Do They Use Bat Guano For?

There are several uses for bat dung. It can be used as a soil conditioner, enriching the soil and improving drainage and texture. Bat guano is a suitable fertilizer for plants and lawns, making them healthy and green. It can be used as a natural fungicide and controls nematodes in the soil as well. In addition, bat guano makes an acceptable compost activator, speeding up the decomposition process.

How to Use Bat Guano as a Fertilizer

As a fertilizer, bat dung can be used as top dressing, worked into the soil, or made into tea and used with regular watering practices. Bat guano can be used fresh or dried. Typically, this fertilizer is applied in smaller quantities than other types of manure.

Bat guano provides a high concentration of nutrients to plants and the surrounding soil. According to the NPK of bat guano, its concentration ingredients are 10-3-1. This NPK fertilizer analysis translates to 10 percent nitrogen (N), 3 percent phosphorus (P), and 1 percent potassium or potash (K). The higher nitrogen levels are responsible for fast, green growth. Phosphorus aids with root and flower development while potassium provides for the plant’s overall health.

Note: You may also find bat guano with higher phosphorus ratios, such as 3-10-1. Why? Some types are processed this way. Also, it’s believed that the diet of some bat species may have an effect. For example, those feeding strictly on insects produce higher nitrogen content, whereas fruit-eating bats result in a high phosphorus guano.

How to Make Bat Guano Tea

The NPK of bat guano makes it acceptable for use on various plants. An easy way to apply this fertilizer is in tea form, which allows for deep root feeding. Making bat guano tea is easy. The bat dung is simply steeped in water overnight and then it’s ready for use when watering plants.

While many recipes exist, a general bat guano tea contains about a cup of dung per gallon of water. Mix together and after sitting overnight, strain the tea and apply to plants.

The uses of bat dung are wide ranging. However, as a fertilizer, this type of manure is one of the best ways to go in the garden. Not only will your plants love it, but your soil will too.

Gardeners use bat guano as a type of manure fertilizer in their gardens. It helps your plants to thrive and become healthier, stronger, and greener. It also helps considerably with flowering processes.

Bat guano is dried in organic fertilizer form, and you can easily find it in a powder form or as small pellets. When mixed with water, it becomes a slow-release fertilizer with a high nitrogen content, helping all of the flora in your garden thrive.

What is Bat Guano?

Bat guano fertilizer ready for a mid-season application. Source: Chiot’s Run

Guano is the excrement of birds that are found near the sea. Bat guano is essentially bat poop harvested from wild insect-eating bats.

In the 18th century, bat guano was actively harvested from bat caves to make gunpowder. In fact, actual bat cave mines were created to harvest the droppings of bats!

Today, it’s popularly used as an organic fertilizer for plant life. You can use it as a conditioner for your garden soil as well as a nutritious feed for your plants. Once applied, it will improve the growth and structure of your plant.

Bat poop is also an incredible compost activator as it significantly speeds up the decomposition process. Although it’s a bit expensive, it has a long-lasting positive impact on plant growth definitely makes it a solid investment for all gardeners.

3 Benefits of Bat Guano Fertilizer

Here are some glorious benefits of bat poop fertilizer:


Bat guano is chock-full of nutrients that are beneficial for the development of your plant. The fertilizer made of bats’ droppings usually comes with around a 10-3-1 ratio of nitrogen, phosphorus, and potassium. These are the 3 most abundantly used plant nutrients.

The high nitrogen content of bat guano helps your plant leaves become greener in just a few days. This is what makes bat droppings such an effective and useful fertilizer.

The phosphorus in the fertilizer will encourage seed creation and flowering in your plants, while the potassium will help your plants move their liquid content and nutrients more effectively.

The slow-release nature of this bat poop fertilizer provides a continuous supply of nutrients to your plants and garden lawn for at least two to three months after the initial dosing.

Soil Improvement

Bat guano contains microbes that benefit the texture of your garden soil. It also has the potential to enrich the soil and improve its draining properties. Additionally, it helps make dense soils lighter and holds together loose soils.

Plus, guano is not easily washed away from the soil, so it benefits your soil and plants much longer than inorganic fertilizers that are displaced or washed away after a single rainy day.

Microbial Action

Bat guano supplies more than just nutrients to your plants. It also carries beneficial micro-organisms or microbes. Microbes are minuscule single-cell organisms that cannot be seen with the naked eye. The microbes found in bat guano have bioremediation capabilities.

What this essentially means is that the droppings of bats can remove the toxicity of your garden soil. Plus, these helpful microbes loosen the soil which increases its water-holding capacity and air space.

Moreover, these microbes protect your plants by preventing the occurrence of dangerous nematodes and soil diseases. Plus, they are efficient decomposers, so much so that if you want to speed up the decomposition process, simply add bat guano to a compost pile.

These microbes will break down the dried organic material in your soil and turn it into a source of nutrients for your plants. This will also create a soil texture that will retain moisture without overly saturating your plants’ roots.

How to Properly Use Bat Guano as a Fertilizer

A cute little long-eared bat. Source: Javier Abalos

You can either use bat guano in fresh or dried form. Typically, you can find it in powdered or pellet form. Plants that can benefit from guano includes ornamentals, herbs, vegetables, nut trees as well as fruits.

You can incorporate the guano directly into the soil, turn it into a liquid fertilizer and spray it on the foliage or disperse it through an irrigation system.

When applied to plant leaves, guano can protect them from fungal infections. You can use guano as a top dressing fertilizer, either in wet or dried form. Simply mix it into the top layer of your soil prior to planting or during active growth.

Pro Tip: Always make sure to read the instructions on the fertilizer label before using it. Also, if your plants show any sign of distress, immediately stop using guano fertilizer. You don’t want to burn your plants with an overabundance of guano.

When to Use

You can pour it into the soil immediately prior to planting. This will ensure that your garden soil is sufficiently prepared to provide beneficial nutrients to your plants.

You can also add guano fertilizer during the active growing season. Simply make bat guano tea and use it during your regular waterings.

Where to Use

Sprinkle guano powder around the base of your growing plant and water it thoroughly. You can also make guano tea and spray it on the leaves of your plant to protect it from fungal diseases.

The best way to utilize the full potential of guano is to brew an aerated compost tea out of it. To make bat guano tea, you need to add liquid or powdery guano into warm water, then aerate with an air pump. However, beware that this tea will produce a severely unpleasant odor.

So, here’s how you can make this beneficial tea:

  1. Pour 1 tablespoon (14ml) of bat guano in 32oz (1l) of warm water – make sure it is not hot as that will kill the microbes in your guano.
  2. Stir the mixture well, and turn on the air pump.
  3. Leave the tea to rest and brew overnight.
  4. Use once every week to ensure generous and fast plant-growth.

Or you could follow this recipe:

  1. Wrap ½ cup of guano in cheesecloth and steep it in about 1 gallon (4 liters) of water.
  2. Let the tea steep for at least 3 days before using it as a fertilizer.

You can use this guano tea as a foliar spray and apply it directly to the leaves or you can pour it over the roots and soil. Bat guano tea is a great source of abundant nutrition for your plant life.

It will also effectively protect the soil from insects and nematodes. Plus, bat guano tea will ensure that your garden soil retains its moisture without harming the roots of your plants.

The Green Thumbs Behind This Article:
Kevin Espiritu
Founder Did this article help you? × How can we improve it? × Thanks for your feedback!

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Last update on 2020-02-01 / Affiliate links / Images from Amazon Product Advertising API


Volume 14, Issue 1, Spring 1996


By Keleher, Sara

by Sara Keleher

“All things in nature have a purpose. Our challenge is to understand the value of these natural gifts and use them responsibly.”

The man who spoke these words wasn’t talking about plants, animals, or any of nature’s more obvious jewels; he was singing the praises of bat dung. As the owner of Garden-Ville, one of Central Texas’ finest organic gardening emporiums, guano purveyor Malcolm Beck not only sells the pungent powder, he also harvests it every year from nearby Bracken Cave. The cave, which is owned and protected by BCI, is home to the world’s largest known bat colony.

Beck first learned about guano and the abundant supply of it at Bracken Cave from a co-worker at his railroad job in 1959. He tried using the guano as fertilizer for his vegetable garden and was amazed at the results. He didn’t know that generations of area residents had been extracting, selling, and working with this natural plant fertilizer and soil builder since at least the late 1800s.

In fact, bat guano has been used in agriculture in many regions for hundreds of years. In the 1600s in Peru, the Incas valued guano so highly that the punishment for harming the animals that produced it was death. During the late 19th century, it had become important enough to American farmers that the government offered free land to those who discovered guano deposits, provided the harvest was made available to U.S. citizens.

Guano was somewhat forgotten once chemical fertilizers became the plant food of choice, but it has always been prized by organic growers. Now that the risks of synthetic gardening products are becoming widely known, more and more farmers are realizing that this dark, rich manure is indeed one of nature’s treasures. For Malcolm Beck, it is an alternative to a shelf full of chemical products, ably serving as plant fertilizer, soil builder, soil cleanser, fungicide, nematocide, and compost activator. His enthusiasm is the result of years of experimentation with organic fertilizers and soil additives, and his experiments are supported by the experiences of countless customers who also swear by guano.

According to Beck, bat guano can be safely used as a fertilizer, both indoors and outdoors, and will benefit vegetables, herbs, flowers, all ornamentals, and fruit and nut trees. Its primary ingredients are roughly 10% nitrogen, 3% phosphorous, and 1% potassium. The high nitrogen content is responsible for plants’ healthy green color and their rapid growth after application. Phosphorous promotes root growth and flowering, and potassium encourages strong stems. Besides these three major nutrients, guano contains all of the minor and trace elements necessary for a plant’s overall health. Unlike artificial gardening products, guano contains no fillers. And, while most chemical fertilizers leach out of the soil soon after being applied, Beck notes that guano remains much longer, enhancing the soil and slowly continuing to feed the plant.

He has also found that guano “works wonders” as a soil builder and says it can be used year-round to improve soil texture and richness, helping to bind loose soil and lighten heavy soil. Homeowners have reported to Beck that the benefits of a single treatment on the lawn can still be seen three or four years later.

Because guano is rich in bioremediation microbes, which clean up toxic substances, Beck touts it as a purifying addition for gardens in transition from chemical to organic practices. He also reports that these microbes will combat fungus when sprayed directly on a plant’s leaves. Finally, Beck reports that bat guano contains powerful decomposing microbes, which help control soil-borne diseases and harmful nematodes and which serve as ideal compost activators, significantly speeding the decomposition process.

The guano cycle begins with plant matter that is eaten by insects. The insects in turn are eaten and digested by bats. After the bats deposit their waste on a cave floor, it is processed once again by millions of beetles and billions of decomposing microbes. What’s left is perfectly preserved and protected inside the cave–a natural fertilizer warehouse.

Guano should not be harvested when bats are present. At Bracken Cave, harvesting is never scheduled until after the bats–some 20 million Mexican free tails (Tadarida brasiliensis)–have migrated south for the winter (typically in early November) and the guano has had a few weeks to dry. Beginning the process during the bats’ stay would disturb them needlessly and could jeopardize their survival.

In the late 1800s, a vertical shaft was constructed at Bracken Cave to extract the guano. Unskilled laborers worked inside, shoveling the harvest into buckets, which were then hoisted up through the shaft. Although the process has been modernized, the guano is still extracted today through the same 100-year-old shaft. In areas of the cave not easily accessible to humans, a large hose attached to an industrial vacuum truck is inserted through the shaft, and the cave floor is vacuumed. This method is automated and fast, requiring little manual labor. But because it costs $360 an hour to operate the truck, humans still provide most of the labor in the larger rooms of the cave. Workers shovel the guano into a hopper attached to a pipe that leads to an air compressor above. The compressor creates a vacuum and sucks the guano from the hopper into large bags at the top of the shaft. One day’s work will typically result in 200 bags, or roughly 8,800 pounds, of guano. It takes about 21 days to complete the harvest.

Malcolm Beck probably couldn’t have imagined back in 1959 that the cave his friend casually mentioned would eventually become the source of a purposeful new career. Today he harvests, markets, and sells up to 50 tons a year of Bracken’s bounty. In doing so, he also promotes and financially supports bat conservation. In an era when more businesses are trying to balance environmental responsibility with profitability, Beck demonstrates that intelligent conservation practices often provide substantial rewards for people as well.

Sara Keleher is BCI’s Development Associate.

The Straight Guano: Seven Ways to Use It

1.plant fertilizer–a 10-3-1 NPK composition
2.soil builder–improves texture and richness
3.lawn treatment–promotes growth and healthy color
4.soil cleanser–bioremediation microbes help clean up toxic residues
5.fungicide–combats fungus through foliar feeding
6.nematocide–decomposing microbes help control nematodes
7.compost activator–decomposing microbes expedite composting processes

Two hundred and fifty pounds of guano helped fertilize the pumpkin patch at Illinois gardener Steve Diamond’s house. Diamond’s twelve-year-old daughter illustrates the enormous proportions of the pumpkins, which can gain more than 20 pounds a day at peak season.” At that time, the vines grow about one inch per hour,” says Diamond. “You can almost watch them grow.”

The harvesting of guano perpetuates an age-old connection between bats and people, but can be dangerous for both unless professionally managed. These two Garden-Ville employees are protected from the guano’s intense ammonia fumes and spore-ladden dust by gas masks, and are working in the cave at a time when no bats are present.

Vacuum trucks extract guano from a 100-year-old shaft at Bracken Cave. This modern method of harvesting is far more efficient than the block-and-tackle pulley system used in the past.

All articles in this issue:

  • On the Cover

  • Bat Workers of the British Isles: A Report from Wales

  • Learning about Bats, London-Style

  • The Evolving Role of American Zoos in Bat Conservation

  • Behind the Scenes of the Metro Washington Park Zoo’s Bat Exhibit

  • Zuri Retires at the San Antonio Zoo

  • Members in Action: Randall Foy

  • Conservation Dollars, the Easy Way!

  • Volunteer Opportunity

  • Wish List

  • Members-Only Nights at Bracken Cave this Summer

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