Are pill bugs all the same species?

No, pill bugs are not all the same species. The term "pill bug" commonly refers to members of the family Armadillidiidae, with the most familiar species being Armadillidiium vulgare, but there are several other species within this family and related families. These species can vary in size, habitat preferences, and physical characteristics. Additionally, pill bugs are part of the broader group of crustaceans, which includes a diverse range of species.