A typical fish trap consists of a frame of steel wire around a funnel or heart shape that the desired catch swim into. There are variety of traps depending on it's intended use from large commercial lobster traps to small crawfish traps.
Depending on your region maybe you call them: crawdads, crawfish, or mudbugs, crayfish but they are one of the best baits you can put on a hook. They also taste great steamed and dashed with some seasonings. Both are great excuses for catching some craw...or cray?