Leech rangers patrol the jungle
Doug Yu's group, amongst others, find a new use for leeches! Reviled as bloodsuckers, these worms have turned out to be a sophisticated biological monitoring tool, writes Richard Conniff.
Hard-bitten tough guy Charlie Allnut, Humphrey Bogart’s character in the 1951 film African Queen, wasn’t scared of much. Not much, except leeches. One of the film’s unforgettable moments is when he tears them from his body, muttering “filthy little creatures” and shuddering with revulsion. It is a horror many share. Few think of them the way scientists are starting to, as the most sophisticated and cost-effective biological monitoring tools ever invented.