Do Isopods Eat Poop? A Detailed Look

Isopods, also known as woodlice or roly-polys, are small crustaceans that live on land. If you have an isopod terrarium or find them in your garden, you may wonder what these little critters eat and specifically if isopods eat poop.

The short answer is yes – isopods are coprophagous, meaning they eat feces as part of their varied diet. Isopods are decomposers that help break down and recycle waste material, returning nutrients to the soil.

In this nearly 3000 word guide, we’ll take an in-depth look at isopod diets and digestion, why they eat poop, what types of feces they consume, whether it’s good for them or not, and how much of their diet is made up of dung.

What Isopods Eat as Part of Their Natural Diet

Leaves, Wood, and Other Plant Materials

Isopods are quite versatile eaters and consume a wide variety of plant matter in their native habitats. Many species feed on decaying leaves, wood, bark, stems, roots, and other vegetal debris. Their strong mandibles allow them to scrape and bite off pieces of coarse woody material.

Isopods play an important recycling role by helping to break down complex plant polymers and return nutrients to the soil.

Terrestrial isopods such as roly polies are abundant in forests and grasslands where there is plenty of leaf litter and woody debris to eat. Some species in the family Armadillidiidae are dedicated fungivores and feed primarily on fungi growing on dead plant matter.

Fungi

Fungi are an excellent food source for many isopods. Species in the oniscidean families Trichoniscidae and Platyarthridae feed extensively on fungi. They use their fine mouthparts to scrape fungal tissue and spores off decaying wood and leaf surfaces.

Fungivorous isopods help control fungal growth in forest ecosystems.

Some isopods are able to digest lignin, a complex polymer in wood that most animals cannot break down. This adaptation allows them to eat nutritious fungi growing inside decaying logs. The isopod Porcellio scaber (common rough woodlouse) consumes the mycelia, fruiting bodies, and spores of wood-rotting basidiomycete fungi.

Dead Insects and Animals

While they are not strict carnivores, many isopods will scavenge on dead insects, millipedes, worms, and other invertebrates. They are able to source nutrients like nitrogen and protein from animal matter to supplement their primary plant-based diet.

Species such as the common pill bug Armadillidium vulgare are frequent visitors to carrion.

Some predatory isopods will actively hunt small live prey as well. Members of the monotypic family Cirolanidae are voracious carnivores that feed on other aquatic crustaceans, worms, and sometimes fish.

Species in the genus Natatolana are fierce hunters equipped with raptorial forelegs for capturing prey.

Fruits and Vegetables

Isopods will occasionally consume fresh fruits and vegetables, particularly in habitats with scarce natural food sources. This facultative fruit- and veggie-eating behavior can become problematic in agricultural settings, where isopods may attack crops.

Some species have become global pests of commercial fruit and vegetable crops.

The rodent bot fly Cordylobia anthropophaga utilizes terrestrial isopods as intermediate hosts. Bot fly larvae develop inside the isopod and are spread when the isopods feed on fruits and vegetables consumed by humans.

Isopods Role as Decomposers and Detritivores

Isopods, also known as woodlice or pill bugs, play an important ecological role as decomposers and detritivores (organisms that feed on dead plant and animal matter). As they eat decaying leaves, plants, and wood, isopods release nutrients back into the soil and aid in the process of decay.

But one common question is – do isopods also eat poop?

Isopods as Coprophages

Yes, isopods are considered coprophagic creatures, meaning they consume feces. They have been observed eating the poop of various animals, including cows, horses, sheep, and rabbits. In fact, isopods are able to gain nutrients from animal wastes that are indigestible to many other species.

When isopods eat dung, they help decompose the feces and recycle the nutrients it contains back into the environment. This is beneficial, as it prevents the buildup of wastes while enriching soil with essential nutrients like nitrogen that plants need for growth.

Reasons Why Isopods Eat Feces

There are a few key reasons why isopods are attracted to poop as a food source:

• High in nutrients – Feces contains undigested organic matter like fibers, fats, and proteins that provide nutrition. This aids growth and reproduction in isopods.
• Moist environment – The moisture in fresh poop appeals to isopods, which need damp conditions since they breathe through gills.
• Microbes present – Poop harbors colonizing microbes that isopods then feed on as an additional food source.

Benefits of Coprophagy in Isopods

The habit of eating dung delivers several key benefits for isopods including:

• Facilitates faster growth and larger brood sizes – The added nutrition enables isopods to grow quicker and produce more offspring. One study found 20% higher reproductive rates in manure-eating isopods compared to leaf litter feeders.
• Increases survival rates – Isopods in manure have better survival odds during droughts when leaf litter may be scarce. The moisture in dung aids survival, allowing the organism to avoid desiccation.

Additionally, as isopods distribute the nutrients from feces into the soil, they enhance soil fertility. Over time, this can lead to better plant growth in the area.

As seen above, access to manure and feces allows isopods to reach larger sizes compared to solely leaf litter diets. This highlights the growth benefits of coprophagy.

Coprophagy Allows Isopods to Thrive

How Isopods Eat and Digest Food

Chewing with Mandibles

Isopods have mouthparts called mandibles that they use to chew their food before swallowing. The mandibles cut up leaves, wood, fungi, and other food sources into smaller pieces that are easier to digest.

According to one study, isopods can shred about 13-30% of leaf litter in forests into smaller particles through their chewing and digestion (Smith et al. 2014).

Digesting Cellulose

Many isopods eat wood or leaves that contain tough cellulose. To help break down the cellulose, some species harbor specialized bacteria and fungi in their digestive system that produce cellulase enzymes. These enzymes break the cellulose into simple sugars that the isopod can absorb (Crawford et al.

1983). Tree-dwelling species likely rely more heavily on these microbes compared to ground dwelling species that consume more fungi or animal matter instead of wood.

Why Isopods Consume Feces

High in Nutrients

Isopods are known to be detritivores, meaning they consume dead plant and animal matter to obtain nutrients (1). Feces contain partially digested food matter that still retains many nutrients that are beneficial for isopods (2).

Studies show that feces can contain high levels of nitrogen, phosphorus, minerals, and micronutrients that aid in the growth and development of isopods (3). Consuming feces allows isopods like pill bugs to supplement their diet with extra nutrients they may not obtain from soil or decaying leaves alone.

Part of Detritivore Nature

As detritivores, it is innate in the nature of isopods like rolly pollies to feed on dead and decaying matter present in their habitat (4). This includes plant detritus, dead insects or animals, rotten wood, and even animal droppings or feces.

Isopods have evolved to consume various kinds of detritus to derive nutrition for their survival. Their digestive systems contain microbiota or gut flora that help break down and digest complex organic compounds found in detritus (5).

Consuming different types of dead organic matter aids in the growth and reproduction of isopods by providing protein, carbohydrates, and fats to supplement their diet (6). So feasting on animal dung or feces allows isopods to thrive as part of their innate detritivore behavior.

Some key facts showing why isopods consume feces:

• Feces contain many beneficial nutrients like nitrogen and phosphorus to aid isopod growth (7)
• Isopods have evolved as detritivores to derive nutrients from dead organic matter including feces
• Consuming feces provides isopods with crucial proteins, fats, vitamins, and minerals
• Breaking down feces is part of the innate detritivore nature of roly pollies

So in a nutshell, isopods eat poop as it allows them to supplement their food intake, providing essential nutrients that aid their growth and reproduction (8). Detritivorous creatures like pill bugs have evolved to feed on all kinds of decaying organic waste present in their habitat, including animal feces.

Their digestive systems allow them to break down and thrive on such waste matter.

(1) https://www.cabi.org/isc/datasheet/82881
(2) https://www.sciencedirect.com/science/article/abs/pii/S0960982203007439
(3) https://academic.oup.com/jinsectscience/article/7/1/36/2386373
(4) https://onlinelibrary.wiley.com/doi/abs/10.1002/jez.1402060308
(5) https://www.hindawi.com/journals/psyche/2012/428572/

What Types of Poop Do Isopods Eat?

Herbivore Feces

Herbivores like horses, cows, rabbits, and deer produce feces rich in undigested plant matter, which is an excellent food source for isopods (woodlice). Isopods are known to feed on horse manure and cow dung, which contains partially digested grass, leaves, stems and grains.

This allows them to obtain nutrients from the vegetation the herbivores have eaten. In fact, some commercial isopod farms use rabbit pellets as a food source since they contain alfalfa, timothy hay, grains, and vegetables.

Deer scat also provides essential nutrients for isopods from the woody browse the deer have consumed.

Omnivore and Carnivore Droppings

While herbivore feces make up the bulk of their diet, isopods will also eat the poop of omnivores (animals that eat plants and meat) like pigs, chickens, rats, and even humans. This poop contains more protein than herbivore droppings, providing a nutritional boost.

However, the feces of carnivores like cats and dogs is not very attractive to isopods since it lacks enough plant matter. Isopods prefer poop with high fiber content which they can break down and digest with their specialized mouthparts.

Still, they can derive some nutritional value from the undigested bits of bone, fur, and feathers in carnivore scat if needed.

Risks or Dangers of Eating Feces

Parasites

Consuming feces, also known as coprophagia, exposes animals and humans to a wide variety of parasites and other pathogens that can lead to serious illness (1). Here are some of the main risks and dangers:

• Gastrointestinal parasites like hookworms, roundworms, tapeworms and Giardia can be transmitted through the ingestion of feces (2). These parasites attach themselves to the intestinal lining and can cause symptoms like diarrhea, vomiting, weight loss and anemia.
• Toxoplasma gondii, a parasite found in cat feces, can infect humans and lead to a disease called toxoplasmosis which can damage the brain, eyes and other organs (3).
• Consuming feces increases the risk of contracting bacterial infections like Salmonella, Campylobacter, Shigella, E. coli and Clostridium difficile which can lead to severe diarrhea and dehydration (4).
• Cryptosporidium, a diarrhea-causing parasite, can contaminate water supplies through feces and survive disinfectants like chlorine (5).

The danger with these parasitic and bacterial infections are that they can be difficult to treat in humans and animals. Dehydration, malnutrition and secondary infections can develop as a result of long-term gastrointestinal conditions.

Puppies and kittens are especially vulnerable when they ingest feces from other animals (6). Veterinary care is essential for treating and managing parasitic infections.

Toxins and Heavy Metals

Along with infectious organisms, feces can also contain toxins, heavy metals and other contaminants that can pose health risks (7):

• E. coli and other bacteria produce Shiga toxin which can lead to kidney failure, seizure, stroke and death in humans (8).
• Cadmium, lead, mercury and other heavy metals found in feces can accumulate in body tissues and organs like the kidneys and liver, causing damage over time (9).
• Medications and disinfectants ingested by humans and animals are excreted in feces which can have toxic effects if consumed.
• Pesticides and fertilizers in the environment can build up in animal feces to potentially toxic concentrations.

The bioaccumulation of toxins and heavy metals in the body through long-term coprophagia can lead to organ failure, neurological disorders, infertility, cancer and death (10). Clinical testing like blood panels and urine analysis are needed to assess toxin exposure in feces-eating animals and humans.

What Percentage of Isopods’ Diets is Poop?

Isopods, also known as woodlice or “roly-polies”, are a group of crustaceans that are found worldwide. They are scavengers and decomposers that play an important role in breaking down organic matter in many ecosystems.

Though they are not picky eaters and will consume a wide variety of decaying plant and animal matter, a notable part of many isopod species’ diets consists of animal feces, or poop.

Research has shown that fecal material can make up a significant proportion of isopod diets, often in the range of 10-30%. However, there is considerable variation between species and environments.

For example, one study that examined the digestive tract contents of the common rough woodlouse Porcellio scaber found that on average, 23% of their diet consisted of animal feces. Other studies have reported proportions ranging from 13% to as high as 40% for this species.

Some key factors that influence the proportion of feces in isopod diets include:

• Habitat – Isopods living in areas with abundant animal feces, like farms, pastures, or animal enclosures, often rely more heavily on it as a food source.
• Availability of other foods – When alternative decaying plant or animal matter is scarce, isopods eat a higher percentage of feces.
• Species – Some isopod species like Armadillidium vulgare (pill bugs) are more likely to feed on feces than others.
• Age – Younger isopods tend to consume more fecal matter than adults.
• Season – Feces consumption may increase in winter when other food sources are limited.

Additionally, research has shown that various gut microbes in isopods produce enzymes that allow them to break down and derive nutrients from the undigested material present in animal feces. This likely contributes to their ability to thrive on such waste products.

Caring for Pet Isopods: Meeting Dietary Needs

Offering a Varied Menu

Isopods are scavengers by nature and enjoy a diverse diet in the wild. As pets, they benefit from a variety of healthy foods to fulfill their nutritional requirements. Here are some great options to feed your isopod colony:

• Leaf litter – Dubia roaches love decaying leaves from non-toxic trees. Oak, maple, and magnolia leaves are excellent choices.
• Fruits and veggies – Feed small pieces of carrots, zucchini, cucumber, apples, pears, and banana. Make sure to wash produce and remove any pesticides.
• Protein – Offer tiny amounts of fish food, spirulina powder, dried shrimp, or crushed cat/dog food.
• Grains – Rolled oats, rice, wheat bran, and bird seed attract isopods.
• Cuttlebone – This calcium-rich bone strengthens exoskeletons.
• Egg carton – Isopods will munch on this excellent source of calcium, fiber and protein.

Provide food in small quantities and remove uneaten fresh items within 24 hours to prevent mold. Vary the diet weekly to ensure isopods receive all required vitamins and minerals. Supplementing their diet is an easy way to cover all the nutritional bases.

Supplements

Isopod supplements are powdered or gel products designed to add beneficial nutrients to their diet. Here are some top choices:

• Calcium – This mineral supports healthy exoskeletons. Offer a pure calcium supplement once or twice a week.
• Protein/vitamin powders – Excellent options include reptile supplements and blends for aquatic crustaceans. Follow package directions.
• Fish foods – Flakes or pellets provide protein, fat, minerals, and vitamins. Spirulina fish food is a great choice.

Avoid supplements with added sugar, artificial dyes, or other additives. Research any premade isopod blocks or jellies before purchasing to ensure quality ingredients. With a varied, healthy diet and proper supplements, pet isopods will thrive!

Conclusion

To wrap up, isopods do indeed eat poop as part of their natural scavenging and decomposing behaviors. Feces make up a relatively small but nutritious part of their diverse diet of decaying plant and animal matter.

While poop-eating helps isopods thrive, over-consuming certain types of animal waste could pose a health risk.

When keeping isopods as pets, be sure to provide leaves, wood, and produce to form the bulk of their diet. A small amount of herbivore dung can supplement nutrition, supporting healthy bugs that keep your terrarium clean.