Land leeches are native to Madagascar and India and the islands of Indonesia, but there are some species found in Japan. Currently there are 60 species known to science, of which 50 belong to the Family Haemadipsidae (literally “Blood – thirsty”), while the rest are in the Family Xerobdellida. While leeches have been known to mankind for a long time, not a lot species had been described and more and more species are being discovered every year. A lot of natives, as well as scientists, call this animal one of the most annoying creatures they had ever seen. Land leeches are known to bite through cloth, get inside your clothing and cover every inch of bare skin you can offer them.
Leeches are simple organisms, most comparable to the normal earthworm that can be found in plain dirt. They have however evolved some special adaptations for their blood-sucking lifestyle. These include two suckers as well as three “jaws.” A posterior (meaning “end”) sucker with an anus, as well as an anterior or “head” sucker with the mouth, allow the leech to cling onto unsuspecting hosts and move like a caterpillar at great speed – this method of locomotion is called “looping.” The jaws are in fact three sharp teeth, used to pierce the skin of smaller animals, or even larger mammals with ease.
Land leeches are known for their sometimes bizarre hunting methods. While most water leeches actively hunt for prey, land leeches hunt inactively similar to ticks. They wave around their heads to sense their environment, using their chemoreceptors. When they find prey they attach themselves and start to pierce the skin in order to get to the blood. Leeches can store blood for months, making them a walking blood bank for researchers in the rainforests. There have been multiple studies on “storage blood” of leeches in order to assess the biodiversity of prey-animals.