Hagfish eat invertebrates (animals such as worms) and are also scavengers, eating fish which are dead or dying. Hagfish have four sets of teeth on their tongue to bite pieces of flesh from its prey. They use these tongue teeth to eat. The teeth pinch together to lock onto its food, helping it tear into dead and dying fish which have sunk to the bottom of the sea, where it lives. Often, a hagfish digs into the dead fish that it is eating, removing the insides of the dead fish.