When they are actively feeding they would eat anything of similar size and shape, for instance when they are gorging themselves on a school of shad. If fishing minnows I believe the struggle of the minnow causes them to key in on an easy meal. When dock shooting I het a lot of light bites. I believe that is from the jig falling right in front of the fishes face and them grabbing it.
I know even if I am not hungry if there is a lot of food around I will eat something.