Stress can put anyone on edge, and venomous snakes are no exception.
New research suggests that habitat loss, climate change, and other human-driven environmental stressors prompt cottonmouths to attack people more often than they otherwise would—a finding that turns a longstanding depiction of the snake as malicious aggressors on its head.
Cottonmouths, also called water moccasins, have a fearsome reputation due in part to their propensity to stand their ground and flash the white insides of their mouths when threatened. Though rare, their attacks can be deadly—a man was killed in Missouri in 2015 after being bitten on both legs while wading through a river. “One of the things people often say is that if you threaten a snake, it’s going to be more likely to bite you,” says Tracy Langkilde, the head of the biology department at Pennsylvania State University and a coauthor of a study recently published online in Genetics and Comparative Endocrinology.
Langkilde and her colleagues wanted to see if this belief was true, so her coauthors set out in snake country in Georgia on a sting mission to aggravate cottonmouths. The researchers approached within a yard of 32 of the snakes then grabbed the middle of their bodies with special tongs, noting whether the animals tried to strike or threaten them. They then put the vipers into buckets and grabbed them again with the tongs after half an hour, noting their behavior once more.