They eat and tats what gives them energy.
Everyone who eats, get energy form that.
Pill bugs get energy from..
"In the wild, pill bugs eat mostly decomposing vegetation -- vegetables, fruits, plants, grasses and weeds. When raising pill bugs in captivity, you can feed them fish flakes, apples, carrots, potatoes, lettuces and wild leaf litter."
Hope this helps:)!
@SamSamySamantha