If you’re going up against a mama mouse, it pays to have a tough skin. That’s how the Calabar burrowing python (Calabaria reinhardtii), a 1-meter-long African serpent that eats nothing but baby rodents, withstands bites from their fierce mothers. Now, a new study suggests the Calabar’s skin may be thicker and harder to pierce than that of any other snake. To measure its toughness, a team of scientists pitted it against the skin of 13 other species of snake, assessing thickness with a microscope and puncture resistance with hypodermic needles and a force transducer. The researchers found that Calabar skin was 15 times thicker and orders of magnitude harder to pierce than that of any other snake tested, they report in an upcoming issue of the Journal of Morphology. Under magnification, color-stained cross sections revealed highly organized layers of collagen beneath its scales. Bundles of collagen in each layer run perpendicularly to those above and below—a tough criss-cross arrangement similar to patterns seen in rhinoceros hides. Even so, the snake’s skin remains flexible—a combination that has already piqued the interest of one pharmaceutical company trying to make tough medical gloves that don’t restrict movement.