Armadillidiidae is a family of woodlice, a terrestrial crustacean group in the order Isopoda. Unlike members of other woodlouse 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. It is this ability which gives woodlice in this family their common name of pill bugs, roly polies, chiggy-wigs or potato bugs. The best known species in the family is Armadillidium vulgare, the common pill bug.
Because of their unusual yet non-threatening appearance, some Armadillidium vulgare are kept as pets in areas throughout the U.S., typically among children. Among adults, they are often seen as unwanted (but essentially harmless) home pests. Keeping a pet pill bug requires a very moist habitat with limited light and lots of decaying plant matter They can often live up to three years. (Source)
During my whole childhood I played with pill bugs. I have felt a little bit guilty since then because I tortured and killed many of them. They become an important component of my childhood. It always called my attention its ability to roll into a ball (a transition from a flat plane to a sphere).
I think they are amazing living things and as I child I always complained because I could not understand how come pig bull were no presented in cartoons ( rabbits, cats and rats were more popular).