"Please tell me how big
they get." Calm down. About the length of a man's forearm. (This is Roy Sawyer's forearm.) When fully stretched out, that translates, in the largest specimens, to 18 inches long. How would you like to have that squeezing between your bare toes? Squeezing through tight spaces is, in fact, a leech specialty. One expert describes how he closed his fist tightly on a leech, but it still managed to push its way out between his fingers. The giant Amazonian leech is no less hardy. Mark says you could probably step on one and not kill it. And leeches in its family can lose up to 80 percent of their body water and survive. Mark tells the story of some captive leeches that escaped and ended up in the back of a pickup truck in the hot sun for a day and a half before being found. The poor shriveled things were plopped in water and, within hours, they'd hydrated back to their old selves.