Leeches are native residents in our local lakes.

Often called bloodsuckers, Leeches are an important part of the natural food web in lakes. Most species of leech feed on worms, snails and insect larvae. Some species prefer vertebrate hosts such as fish, reptiles and mammals. Leeches are a food source for vertebrates such as fish, ducks, and turtles. They are typically found in shallow, protected water, among aquatic plants or under stones, logs and other debris.

Most leeches feed by sucking blood from their hosts.

A leech can ingest several times its own weight in blood after which it will drop off and seek a hiding place. It will not feed again for weeks or even months. Leech saliva contains an anesthetic so their victims do not feel them break the skin. It also contains an anti-coagulant, called hirudin, which passes into the wound to facilitate the flow of blood.

Summertime means more leeches.

Leeches reproduce in the spring. The young leeches are out of their cocoons several weeks later, just in time for swimming season! While generally nocturnal creatures, leeches are attracted to water disturbance created by swimming and wading. Leeches prefer the shallow, protected areas of lakes. They also prefer areas with aquatic weeds, submerged branches, or other debris on which to attach themselves or to hide. Swimming in deeper waters and in areas free of plants and debris will reduce the likelihood of a leech finding you.

A leech on your skin after swimming or wading, don’t pull it off!

The mouthparts of the leech could remain in the skin and cause infection. Use of an irritant, such as salt or heat, will make the leech let go. Clean, disinfect and bandage leech bites to prevent infection. A leech bite may ooze for several hours. This is caused by compounds present in leech saliva that reduce blood clotting. There may also be irritation or itching after a bite, similar to that of a mosquito bite. If the wound doesn’t heal properly, contact your doctor.

Can you get rid of leeches in your swimming area?

There are no chemical control measures that will effectively reduce leech populations without causing harm to other beneficial aquatic animals including fish. Because leeches like to conceal themselves under sticks and other debris, keeping swimming areas free of such material may help reduce the human/leech encounter. However, to maintain a healthy shoreline, leave the natural vegetation on the shore and in the water.