6 serious facts about the playful-looking roly-poly

March 28, 2019, 8:21 a.m.
pill bug or roly-poly
Photo: Mauro Rodrigues/Shutterstock

Almost everyone loves a pill bug. Or maybe you know them as roly-polies, doodle bugs or wood shrimp. Kids are fascinated by these tiny little critters that defensively roll up into a tight little ball when disturbed. That's a process known as conglobation. But there's so much more to these familiar creepy crawlies than their acrobatic prowess. They play an important role in the environment.

But first, some trivia.

Interestingly, they're not even bugs. They're actually crustaceans, not insects. They're more closely related to lobsters, crabs and shrimps than to beetles or butterflies. They're the only crustaceans that have adapted to living completely on land, according to the University of Kentucky Entomology.

And they have some unusual bodily functions. They don't urinate, having no need to excrete ammonia-heavy waste out of their bodies. They also eat feces, including their own. When it comes to drinking, they use tube-shaped structures that jut out of their rear ends, not their mouths.

As for breathing, they have gills, like their ancestors. Those work great in the water, points out KQED Science, but not so great on land, where they can dry out. That's why pill bugs are often found in wet, damp areas where they can roll into a ball to protect any moisture they have on their gills.

The pill bug's many jobs

Other than entertaining children, the pill bug plays several key roles:

They 'eat' metals. Pill bugs can take in heavy metals such as copper, zinc and lead, and they crystallize them in their bodies. They are able to remove heavy metal ions from contaminated soil and can thrive in places where other species can't.

They compost soil. Pill bugs feast on dead, organic matter, thanks to the fungus in their guts. This helps speed up decomposition. Then they return organic matter back to the soil so it can be digested even more by fungi and bacteria, reports Natural News.

Pill bugs slow climate change. As the atmosphere gets warmer, there's more fungus activity in the earth, which means more carbon dioxide is released into the atmosphere. But according to a 2015 study, when pill bugs are around, they eat more fungus, putting a damper on the fungal activity and playing a small role in slowing climate change.