"Roly Poly Bug Facts:Although people refer to the roly polys as bugs, they are not insects. ..

"Roly Poly Bug Facts:Although people refer to the roly polys as bugs, they are not insects. These wingless, 1/2-inch-long, oval creatures are crustaceans -- land-dwelling relatives of lobsters and crabs..."

https://homeguides.sfgate.com/roly-poly-bug-80872.html