pill bug

American  

noun

1. any of various small terrestrial isopods, especially of the genera Armadillidium and Oniscus, which can roll themselves up into a spherical shape.

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pill bug British  

noun

1. any of various woodlice of the genera Armadillidium and Oniscus, capable of rolling up into a ball when disturbed

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Etymology

Origin of pill bug

An Americanism dating back to 1835–45

Example Sentences

A new species of giant deep-sea isopod—a cousin to the common pill bug but more than 10 inches long—was found hiding in plain sight.

From Scientific American

Instead, worms rely on a village of bacteria, molds, fungi, pill bugs and other beneficial microbes to break down the food so they can eat it with their microscopic mouths.

From Los Angeles Times

Like trilobites, three-banded armadillos, pill bugs, hedgehogs and other animals, the chiton can roll itself into a ball.

From New York Times

The pods look like giant pill bugs and travel at a suitable crawl Each pod has a pair of double doors, with two leatherette benches facing one another inside.

From The Verge

Inside their bellies Gerringer found hundreds of tiny crustaceans shaped like the roly-poly pill bugs one might find in a garden.

From National Geographic