Snakes are strange. They move in mysterious ways. Is that even real? Or that? They can even fly. Well, they can glide, which is scary enough. All of these motions involve bending the body — sometimes really bending it. But there’s another way that they move, which is to creep ahead slowly in a straight line using their belly skin. They do this when space is too tight for other movements or perhaps to be very, very stealthy. The movement was first described about 70 years ago by a pioneer in snake locomotion studies, Hans Lissmann. But his hypothesis about precisely how the muscles act to create that movement was never tested — until now. Enter Bruce Jayne, who studies snake locomotion in his University of Cincinnati lab. That’s Teddy, his favorite. Jayne’s lab measured muscle activity by recording electrical impulses. “We had an extremely good idea of all of the movements. But what we were really lacking were any direct observations of how the muscles work.” As Lissmann predicted, three sets of muscles are at work moving the skin forward and pulling the body along to catch up. The muscles in the belly skin act a bit differently than he thought. Those details are important, because a thorough understanding of this slow creeping could be of practical use. “I’ve had collaborations with engineers that have been trying to design snake-like robots to go where more conventional robots would have great difficulty going.” So, robot makers, sidewinding is good. But when space is tight or stealth is necessary, maybe think about making your robot’s skin crawl.