Flatworms feed by extending their mouth parts and sucking the juices from either prey organisms or, when available, animal corpses, as stated by the Northern Virginia Ecological Study database. Flatworms feed on nematodes, rotifers, aquatic worms, soft-bodied animals of all kinds and sometimes members of their own species when other food sources are not available.
Flatworms move underwater by exuding a coat of mucous, enabling them to slide along over most surfaces. They are also small and light enough to move upside down at or near the water's surface, taking advantage of its tension to move about.
The mucous produced by flatworms acts as a secondary hunting tactic. It can trap small organisms, preventing them from escaping and allowing the flatworm to feed on them at its leisure. Flatworms may trap tiny crustaceans and other animals in this manner before returning to feed on them.
Flatworms feed by extracting bodily juices from their prey. Flatworms are opportunistic eaters by nature and will happily consume dread flesh when live prey is unavailable or when an opportunity presents itself. The mouth of a flatworm is specifically configured to allow it to latch onto a food source and slowly siphon out its juices.