Jordan says that leeches don't live long out of water. This depends on the type of leech. Of the several hundred known species of leeches, at least 90 species live on land, usually in moist areas like piles of leaves. On the other hand, land-dwelling leeches are generally tropical and not likely to be found near Boston. Some leeches can also estivate (hibernate) during droughts, losing up to 90% of their body weight to dehydration without permanent injury.