Welcome to Brain Stuff, a production of IHeartRadio.

Hey, Brainstuff, Lauren Vogelbaum here with a classic episode from our archives.

With the weather turning colder here in the northern hemisphere, I was thinking about all of the

cold-blooded critters out there that depend on sunlight and warm temperatures to keep their

bodies going. Here are some of the ways that they survive the winter. Hey Brain Stuff, I'm Lauren

Volgobam, and you and I can complain about seasonal chills all we want, but at the end of the day,

we're basically walking furnaces. Humans are endotherms, meaning that our bodies produce heat internally.

We're also able to maintain a body temperature that stays more or less constant.

So, we should count our blessings.

Not all animals have these physiological advantages.

Apart from a handful of species like the monstrously big leatherback sea turtle,

very few reptiles or amphibians

are able to keep their bodies at a constant temperature. And since they can't warm themselves up,

these creatures must extract heat from their environment. But what happens when that environment gets

colder? How to frogs, snakes and turtles make it through the winter months in places that see

blankets of snow, iced over lakes, and sub-freezing temperatures year after year. A lot of reptiles and amphibians

undergo periods of extreme seasonal inactivity. When the weather gets colder, they may experience

decreased heart rates, slowed metabolisms, and lower overall body temperatures. Scientists disagree

over what to call this state.

Everyone accepts that it's some kind of dormancy, but while some experts classify it as hibernation,

others refer to it as brumation. Dormant snakes generally hold themselves up in winter dens. These

shelters may take the form of an abandoned rodent burrow, an exposed crevice on a rock face, or some

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