Leeches are found in lakes, ponds, swamps, marshes and moist soil in habitats around the world. Most leech species exist in shallow water that is slow-moving, but certain species can also be found in the ocean.
Leeches that live in habitats that experience freezing temperatures bury themselves in the mud and remain dormant until the weather becomes warmer. They are often found under rocks and leaves, or at the bottom of shallow lakes and streams. Leeches feed on the blood of mammals, fish, frogs and turtles. When a leech feeds on its host, it releases an enzyme that numbs the feeding area so the host does not feel pain. The enzyme also possesses anti-coagulant properties that allow for free blood flow. Once the leech removes itself from its host, the host's blood continues to flow until the enzyme wears off.