Q. Why do snakes shed their skin?

Joey Feuling

Grade 7

Sennett Middle School

A: Like a growing child outgrows clothes, a growing snake outgrows its skin.

"Reptiles are covered with scales," says UW-Madison wildlife ecologist Scott Craven. Unlike our flexible skin, reptile scales are fixed and do not allow expansion.

"The scaly skin cannot grow with them," he said. Instead, snakes must shed the skin in order to grow.

As a snake gets bigger, Craven says, "The old skin loosens, they break it at the nose, catch it on a rock or twig and just crawl out of it, with a shiny new skin already in place."

Craven said well-fed snakes will grow more quickly and shed more often than hungry ones. "The faster they grow, the more often they shed -- maybe several times in the summer and not at all in the winter."

Other reptiles deal with their scaly skins in a similar way, he says. "Lizards shed as well, but the skin sloughs off in pieces, rather than whole."

Curious? Look for Curiosities on Thursdays in the Local section. Send questions to: bwilliams@madison.com; 608-252-6130; Curiosities, P.O. Box 8058, Madison, WI 53708."