Most folks who’ve enjoyed a dip in the local swimming hole – whether at a pond, lake, or river – have probably found, on occasion, a leech or two stuck to their skin while toweling off afterwards. Although some might think these slimy little suckers are gross, they mean – and do – no harm. They’re just hungry.
“With some 600 species, there’s a surprising amount of diversity,” said Adam Weaver, a biology professor at Vermont’s Saint Michael’s College. And the majority of leeches aren’t even bloodsuckers.
Weaver said scientists estimate about 10 percent of leech species – which are found from the tropics to desert watering holes to Antarctica – are parasitic, and only a couple of the 70 or so freshwater species found in North America are bloodsuckers. The rest get their nourishment primarily from eating larvae, invertebrates, and decaying matter. » Continue Reading.