at one time i had a bluegill in a tank and a bumble bee was in my room flying up and down the tanks glass, the bluegill went NUTS trying to get the bee it was biting at the glass and ramming the sides of the tank WOW i was supprised, anyways we caught the bee and put it in a small jar with a crayfish, it was crushed and drowned........ and the moral of the story is that most fish like to eat bugs