Pill Bug (Armadillidium vulgare)

Are you looking for an unconventional pet that is easy to care for and also provides hours of fun watching it in action?

Then look no further than the Pill Bug, or Armadillidium vulgare, an isopod species found in most parts of the world.

Instead of seeing them as a common garden nuisance, you can use this care guide to transform them into the next best pet in your home! 

Common Name Roly Poly Bug, Pill Bug, Potato Bug, Pill Woodlouse
Family Name Armadillidae
Scientific Name Armadillidium vulgar
Use Cleaning, Aerating Soil, Feeders
Temperament Non-aggressive
Lifespan 1-3 Years
Diet Detritivore
Adult Size 0.5-1.27 cm
Breeding Type Egg Layer
Care Level Easy
Minimum Tank Size 2-5 Gallons
pH 6.5-8.0
Hardness Soft
Temperature 69-77°F

What Are Pill Bugs?

Native to Europe and a number of other parts of the world, Pill Bugs belong to the family Armadillidiidae and the genus Armadillidium.

Most commonly known as “Roly Polys” and “Pill Woodlouse”, this species of isopod gets its name from its ability to curl itself up into a tight ball for protection.

Rolie Polies prefer damp, dark, and humid conditions, so they are often found in areas near streams or moist woodlands.

What Do Pill Bugs Look Like?

Pill Bugs are small, armor-plated crustaceans with oval, convex bodies and two small antennae at the front.

Armadillidium vulgare as a species can grow up to be 0.25 to .5 inches in length. Roly Poly Bugs range in color from gray to black, with some having a blueish tint.

This species of isopod has 7 movable body segments, each protected by a hard, single-piece exoskeleton.

On the underside, there are four pairs of legs, all ending in characteristic paddle-like shapes.

Pill Bugs also have two tail-like appendages called uropods, which help them roll up into a ball when disturbed.

Benefits Of Using Pill Bugs

Live Pill Bugs make for a great addition to vivariums, and not just for their aesthetic value.

Not only are they small and easy to care for, but they are also beneficial to the overall ecosystem in bioactive terrariums.

Armadillidium vulgare feed on dead and decaying matter which helps break down organic material and aerate the soil.

They also add additional protein and fat to the soil and can help regulate the population levels of other inhabitants in the tank.

Additionally, watching the Pill Bug move and forage for food can be surprisingly entertaining for the observer.

Best of all, having live Rolie Polies in any enclosure is a great way to introduce kids to learning about and caring for small organisms.

Pest To Pets: A Pill Bug (Armadillidium vulgare) Care Guide

Pill Bug Facts

Pill Bugs are small terrestrial crustaceans that measure 1/2 of an inch long and have an exoskeleton composed of seven overlapping flexible plates.

In both the wild and in captivity, they are opportunistic detrivores.

Males can be distinguished from females by their longer antennae and a distinct groove on the underside of their last joint.

Although they can live for up to three years in captivity, they typically reach maturity after four months.


Pill Bugs, or Armadillidium vulgare, are native to many parts of the world, with the discovery of their origins dating back to the late 1800s.

They are one of the few species of isopods and can be found in coastal areas, gardens, moist habitats, or any area where there is a lot of damp organic matter.

In the wild, these scavengers can be unearthed from rotting wood, under logs, and in jumbled-up piles of leaves, bark, and other organic material.

They particularly love moist environments with lots of decaying vegetation because it provides them with ample food sources.


In their natural habitat, Pill Bugs feed on components of decaying organic matter such as dead leaves, decaying wood, fallen fruit, and even live plants.

They also eat fungi, algae, small amounts of healthy soil, and other plant matter like fines and small pebbles.

Armadillidium vulgare tends to be most active after rainfall and during warm, humid days. They usually are spotted in shady areas, but they also often come out in the sun during warm days.

Pill Woodlouse can survive without water, but they will drink it if it’s available. They mostly consume it through the food they eat.


Pill Bugs are known for having a peaceful temperament and usually stay away from humans and other animals.

They are also surprisingly fast and agile as they can roll up into tight little balls when startled.

They also tend to live alone, making them the ideal pet if you need something that is low maintenance and easy to care for.

Although they are harmless and won’t cause any damage to your garden, if handled roughly, their spiky exoskeleton can deliver a scratch or two if handled carelessly.

They don’t usually compete for food, or bother each other, but can make great friends if they are housed together in the same terrarium or habitat.


Pill Bugs have a relatively short lifespan of up to three years and can reproduce twice in the span of their life.

They go through three life stages: egg, juvenile, and adult. During the spring and early summer months, female Rolie Polies will lay up to 200 eggs that hatch during the summer.

Within three to four weeks, these juvenile Pill Woodlouse will reach their adult stage and have a lifespan of several months.

They reproduce a second time during the fall months, ensuring that the next generation of Pill Bugs will make it through the winter.

During the winter season, Armadillidium vulgare becomes inactive and enters a type of hibernation to prepare for the warm weather and the new growth.


Armadillidium vulgare mate and reproduce in a typical way for isopods.

An adult male will approach a female and initiate the mating process by tapping her shell with his antennas.

When she accepts his mating attempt, the male will embrace the female and create a sperm packet.

The female will then form a brood pouch on the underside of her body to hold the sperm packet.

After mating, the female is capable of producing anywhere from 10-15 eggs at a time.

These eggs will remain in her pouch until they hatch, which usually takes between 7-14 days. The baby Pill Bugs, which are called nymphs, will then be released into the environment.

Nymphs look like smaller versions of adults, but they will molt a few times before they reach adulthood.

During the adulthood period, they will undergo multiple mating sessions in order to produce more eggs.

Where To Find Pill Bugs

Finding wild Pill Bugs or those for sale is relatively easy, as they are widely distributed across the world.

Although you may come across them in gardens and parks, Rolie Polies prefer moist wooded areas and other fairly shaded spots where they can hide from predators.

Pill Bugs are also widely available for sale, either in bulk or individually, from pet stores and online retailers.

Most Roly Poly Bugs sold commercially are cheaper than a single pet, although prices may vary depending on the supplier.

Pill Bug Care

Caring for Pill Bugs involves providing an appropriate habitat with a source of humidity, food, and shelter.

It is also important to ensure the habitat is clean, properly maintained, and monitored regularly for health-related issues.

Armadillidium vulgare should be kept at temperatures between 64°F and 80°F and require periodic feedings of produce and animal-based food sources.

Tank Requirements

When setting up the ideal tank for your Pill Bugs, you’ll need to make sure you pay attention to several factors.

The ideal vivarium type will depend on the size of your Roly Poly Bug colony and how much space you have; many opt for glass enclosures.

Ensure the pH of your tank is neutral to slightly acidic, the hardness is less than 10 dGH, the temperature is between 70-80 degrees Fahrenheit.

the ideal terrarium substrate should be peat moss or coco fiber, and the terrarium lighting is moderate and used only to provide visual cues.

Additionally, you should ensure your tank has enough hiding places, such as leaf litter and hollow vivarium wood, so your Pill Bugs can feel secure and happy.

What Do Pill Bugs Eat?

Feeding your Pill Bugs is an essential part of caring for them and providing them with the nutrition they need to remain healthy.

Remember that Armadillidium vulgare are detrivores, meaning they will feed on both decaying plants and small insects.

Here are some of the items you can feed your Pill Bugs:

  • Leaf Litter
  • Small pieces of Fruit and Vegetables
  • Fish Flakes
  • Crushed Mealworms
  • Dried Bloodworms
  • Special Pill Bug Feed

If you’re more of an avid hobbyist like myself, be sure to check out my ultimate DIY Isopod food guide. I give a more in-depth explanation of the best foods and my personal favorite recipe.

What Do Isopods Eat? + A Fun DIY Isopod Food Recipe!

Best Tankmates For Pill Bugs

When it comes to tankmates for Roly Poly Bugs, look no further than other species of isopods—like Cubaris and sowbugs—which all offer similar beneficial qualities and make great tank mates.

They will coexist in the same enclosure and can be fed the same food, plus they provide excellent companionship for Armadillidium vulgare.

It’s also a good idea to consider some species of roly polys—like Armadillidium pictum and Armadillidium nasatum—as they are closely related to Pill Bugs, and will be similar in size, activity levels, and behavior.

In addition, springtails can also thrive with Pill Woodlouse and make great tank mates.


This care guide is all you need to get started when it comes to adopting and caring for Pill Bugs.

With the right habitat and diet, along with timely treatments for any potential diseases or parasites, it’s easy to create a safe and happy home for your new terrarium pet.

So take the plunge and learn to love these fascinating creatures.

Frequently Asked Questions

No, pill bugs (Armadillidium vulgar) are not harmful. They do not cause any direct harm to humans or possessions and are considered to be beneficial for indoor environments.

Pill bugs (Armadillidium vulgar) are attracted to moist, dark areas and decaying organic matter, such as rotting leaves and wood.

Pill bugs may enter your home in search of food, moisture, and shelter. They may enter through small cracks in the foundation, between gaps in the walls or window frames, or by latching onto objects.

Yes, pill bugs can infest your house if the humidity and moisture levels are suitable for them. They can enter through small openings or gaps in walls and other structural components of the house.

Yes, pill bugs benefit the environment, as they feed on dead plant material and help break down organic matter for reuse. They are also an essential food source for small wildlife such as birds, frogs, and lizards.

Rolly pollies eventually transform into adults after going through several stages of molting.

The lifespan of a Rollie Pollie is around 23 years.

Roly poly bugs can be killed by predators, pesticides, and diatomaceous earth.

Animals That Eat Roly Polys:

– Frogs
– Toads
– Fish
– Turtles
– Newts
– Lizards
– Salamanders
– Birds
– Insects

No, rolypoly bugs are not cockroaches. Rolypoly bugs, also known as pill bugs or woodlice, are terrestrial crustaceans in the order Isopoda, while cockroaches are insects in the order Blattodea.

Yes, it is safe to touch Rolly Pollies, also known as pill bugs. They are harmless crustaceans that will curl up in a ball when disturbed.

No, pill bugs do not carry diseases that can be transmitted to humans.

If a rolypoly  bites you, it would typically just pinch and not cause any lasting harm. Rolypolys are harmless creatures and neither sting nor bite.

Yes, pill bugs have the ability to remove heavy metals from contaminated environments. This process, known as biosorption, involves the pill bug taking up heavy metals from the soil and storing them in the cell walls of the bug.

Pill bugs are most active at night and during times of high humidity.

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