Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent every weekday. Winter has officially arrived in the Northern Hemisphere. With today’s winter solstice, the days will start to get a little bit longer, but the cold will stick around. We humans typically handle the dipping temperatures by staying inside, sleeping more, and dressing in layers. But what about other members of the animal kingdom? Here are some unique ways that animals survive winter’s deep freeze.  Brumation nation To fend off winter’s chill, some reptiles and all amphibians brumate. Brumation is basically a less intense form of hibernation. Bears and other mammals who hibernate spend a lot of the time sleeping. Instead, brumating amphibians and reptiles go through a period of dormancy with small bursts of activity.  “During the winter, brumation is like taking a long nap, getting up when it gets a little warmer, going to the bathroom, drinking some water, and then going back to sleep,” Karen McDonald, the STEM program coordinator at the Smithsonian Environmental Research Center in Maryland tells …