Leeches eat small insects and molluscs some can even eat small fish Leeches are eaten by fish... in fact they are used as fishing bait especially for catfish and salmon Leeches can also drink blood. some are even used in medicine to drink bad blood or eat dead skin.
Leeches are from the subclass Hirudinea and a kind of segmented worm but differ in significant ways. Leeches eat a prey on small invertebrates, and they use their interior suckers to feed on their host.
No, leeches stand little chance of catching the very quick mosquito larvae. Leeches tend to feed on fish, often attaching themselves to the fish right before they are swallowed and then moving to the gills where they suck the fish's blood.
Leeches are flat worm-like animals found in ponds and lakes. To keep leeches under control in a water setting, it is important to have fish around that will eat the leeches. Redear sunfish are good leech eaters.