When he is not rummaging through my compost pile for discarded food scraps, the black bear tears apart ant hills and rotting logs looking for ants and other insects. He also picks blueberries, raspberries and blackberries that grow in Petra, Maine. Bears also feed on the bark of trees and the soft cambium layer beneath. Fortunately, trees grow like weeds in Petra, so the bear is welcome to eat some of our trees.