Anything. The best bait I have found for most cats is cheese. The stankier the better. But, I've also caught them on crankbaits, woolybuggers, zonkers, minnows, worms, and bacon. If your after channels, the best I've found is a good ole nightcrawler, blue, white or flatheads like smaller fish, and bullheads by far the best is cheese, although worms work, as will smaller baitfish.