Where we fish, we use chunks of smelt, and they absolutely inhale those. Makes it tough to release one, though. As others have said, they have zero teeth, so lip 'em if you can. The ones we have in Montana have a habit of locking their jaws shut like a vice grip upon contact with the surface, which makes lipping them a bit of a challenge. Depending on the size of the fish, we typically just horse the slimy devils out of the water.