Spiders freak people out just by existing, but they also have a quality some might consider creepy: They shed their skins.
Regular skin peels are routine for other creatures, too, which inspired Weird Animal Question of the Week to look into this intriguing process of renewal. (See 10 beautiful pictures that will make you love spiders.)
Growing larger causes spiders to molt, a process called ecdysis, Jo-Anne Sewlal, an arachnologist at the University of the West Indies, says via email.
Tarantulas, as the above video shows, “secrete a new exoskeleton around itself while it is still encased in the old exoskeleton,” Sewlal says. (See “Bondage, Cannibalism, and Castration—Spiders’ Wild Sex Lives.”)
The living tissue between old and new will dissolve, except for nerve connections to sensory organs like eyes and touch-sensitive hairs.
To get things going, the tarantula contracts its abdomen to push fluids into the cephalothorax, its fused head and upper body. This pressures weak spots in that segment so the old exoskeleton “lifts off like a helmet,” Sewlal says.
Finally the spider flips over and slides out of its old legs like a pair of jeans—et voilà, the tarantula’s new clothes. (Also read “50 New Spiders Discovered In Australia.