Crappie can be caught on leeches, but most anglers usually don’t use leeches for crappie. If you are going to use leeches for crappie, the smaller leeches typically work better. Some anglers do have success by tipping their jigs with small pieces of leeches. If you cut the leech in half or into thirds, these pieces can be very good on the back of a hair jig and it will stay on the hook for a while. You can use this technique, however, you will probably do much better with minnows instead.