Naemanson, bullheads here are little fish we use as bait... as "I'm going to go screen some bullheads". You take a window screen, stand in a relatively shallow creek and place one edge against the creek bottom, while you have another person turn over rocks upstream. I did this years ago, and now that I think of it, I have no idea if it is legal or not to do this! You catch the bullheads in the screen, then go to a big river and use them for bait for big trout. (more thread creeping)