Leeches look like segmented worms with suction cups at both ends. They are dark brown to black, can be plain or have spots or stripes, and are usually no more than 6 inches long.
Leeches tend to live in shallow, dark water that provides a lot of organic cover. Their favorite place to live is in a swampy area. They are found in temperate climates all around the world.
Not all leeches are bloodsuckers. Those that are have a special chemical in the saliva that prevents blood from clotting. These animals began being used in medicine in the 1800s and are still used today, most commonly to remove congested blood from a wound.
Leeches not fond of blood feed on insects, snails, worms, and small invertebrates. Many species of leeches engulf their prey and swallow it whole.