What Did You Call These, When You Were Growing Up?

Riddle: What has seven legs, two antennae, and rolls up into a ball?
Answer: A roly-poly (also spelled rollie pollie)!

A roly-poly, also known as a pillbug, is one of the many helpful macro-organisms that can live in healthy soil or compost. Along with creatures like beetles, spiders, and flies, roly-polies support a soil ecosystem by helping with aeration and speeding up the breakdown of organic matter.

Even though people call them “pillbugs,” they are not insects. Roly-polies are actually crustaceans, related to shrimp and lobsters, and they belong to the Armadillidiidae family.

What a Roly-Poly Looks Like

Roly-polies have a hard outer shell called an exoskeleton. They have seven legs and two antennae, and their most famous trick is curling into a tight ball to protect themselves from predators.

When they’re stretched out, most are about 1 inch long. Healthy roly-polies are usually brown to gray, though rare color changes (like bright blue or purple) can happen and may signal stress or illness.

Where They Live

Roly-polies prefer dark, damp places. You’ll often find them under leaves, mulch, or rocks, and they can also show up in compost bins, especially where there’s rotting fruit.

Why Gardeners and Composters Care

For composters, roly-polies can be excellent decomposers. They feed on decaying plants, dead insects, and animal matter, helping to break down organic material faster and return nutrients back into the soil.

However, they aren’t always harmless. In some gardens, roly-polies may nibble on fresh vegetation, especially tender seedlings. The good news is that they typically can’t chew through thick, mature plants, so they’re rarely a serious threat to most established vegetables.

Conclusion

Depending on who you ask, roly-polies are either a helpful garden ally or an occasional pest—and some people even keep them as simple, low-maintenance pets (kids and adults alike). There’s something oddly satisfying about watching one curl into a ball and then slowly uncurl once it feels safe.

Like earthworms, roly-polies are not picky eaters, which makes them useful in compost systems. Overall, they’re fascinating little recyclers that can play a valuable role in soil health and composting.