Illinois scientists are studying an endangered species of rattlesnake to find ways to revive its numbers.
The Eastern massasauga once was widespread in the Midwest, living mainly in the Great Lakes region. Over several decades, its population declined dramatically. The species lives in wetlands, many of which have been drained to to build farms. Northern Illinois University biologist Richard King said it's also the only venomous snake in its range, which has made it a target.