It is sometimes called a roly-poly due to its ability to roll into ball when disturbed (Figure 1). This defensive behavior also makes it look like a pill, which is why it is sometimes known as a pillbug.

How did Rolly Pollies get their name?

Unlike members of other woodlice families, members of this family can roll into a ball, an ability they share with the outwardly similar but unrelated pill millipedes and other animals. This ability gives woodlice in this family their common names of pill bugs or roly polies.

Is a roly-poly A pill bugs?

Roly-poly is a common nickname for these creatures, but it's certainly not the only name they go by. ... The official name for these creatures is pillbug. They are also sometimes called woodlice, because they are often found under logs.