Cuddling penguins and snorkeling alligators: What animals do to stay warm during extreme cold

Penguins stay warm through social thermal regulation, a scientific term for cuddling.

(CNN)It's not just humans finding ways to stay warm during this week's historic temperature plunge — our animal friends are too.

And some of the strategies animal use are pretty cool (pun fully intended).
Animals are classified as either endotherms or ectotherms, which is another way of saying warm-blooded or cold-blooded. Endotherms regulate their body temperature by producing heat within. Birds are a good example.
    Ectotherms are the opposite and rely primarily on the surrounding environment to regulate body temperature. Picture a turtle on a log basking in the sunshine on a warm day.
      Every animal, whether it's an endotherm or ectotherm, has a plan to survive the cold, said Justin Boyles, a thermoregulation expert and an associate professor at Southern Illinois University in Carbondale, Illinois. Some animals migrate before the season to avoid it altogether. Some conserve energy and hibernate until its source of food returns during the warmer months. And others have developed ways to just tough out the harsh conditions that sometimes hit.
        The tactics can be fascinating.
        Take the wood frog for instance. "These small frogs survive through an adaption that allows them to freeze itself and then thaw itself to safeguard its organs and energy," according to Leah Neal, an associate curator at the Georgia Aquarium.
          A freezer and a microwave all in one. How convenient!
          What alligators do during extreme cold seems straight from a science-fiction movie. Alligators go into brumation during the cold, which is like a low-scale, short-term hibernation to conserve energy and maintain its body temperature. What's weird about that? When it gets freezing cold, an alligator will stick its nose out of the water to breathe like its snorkeling the beautiful blue waters of the Bahamas. That is what's eerie. You may remember viral images of this alligator from a cold snap in 2018.
          Red bats look a lot like leaves when hanging from a tree. During the cold, a red bat will drop to the ground and cover itself with a litter of leaves like a blanket. Given its outer appearance, it's camouflaged quite well and protected from predators. So, it can sleep peacefully.
          Manatees are extremely susceptible to the cold. A sea cow can't survive in water temperature below 68 degrees Fahrenheit, according to Manatee Lagoon spokeswoman Brittany DiLoreto. When temperatures begin to drop, manatees will take a vacation to Florida — curling up in the Sunshine State's rivers and springs, and surprisingly, even the warm, clean waters of nearby power plants.
          Penguins stay warm through social thermal regulation. This means Mumble from "Happy Feet" and all his friends are huddling and cuddling together to stay warm.
          Boyles, the thermoregulation expert, says normally vicious flying squirrels will sometimes show a softer side and huddle with others to make it through a cold snap.
          But pets are different. They need help.
          Through hundreds and hundreds of years of domestication, most pets have lost the ability to adapt to harsh conditions like wild animals. It's important that pet owners take the necessary steps to protect their four-legged family members during the cold, especially when temperatures drop below freezing.
            The Animal Humane Society of Minnesota offers the following suggestions for protecting your indoor and outdoor pets during harsh winter conditions:
            • During severe weather, dogs should go outside only to relieve themselves and cats should be kept indoors at all times.
            • Put Vaseline or doggie shoes on your dogs' paws before walks to protect him/her from sidewalk salt and chemicals; wipe the Vaseline off when back inside.
            • Remove any ice, salt and caked mud from your pet's paws and fur immediately.
            • Check to see if your pet's bed is in a cold or drafty area of your home. If it is, move it to a warmer location.
            • Feed your dog reduced portions to avoid weight gain. Indoor dogs typically receive less exercise during cold weather and therefore may require fewer calories.
            • Outdoor pets typically need more food in cold weather because they must burn more calories to keep warm.
            • Check your pet for frostbite, especially on paws and ears, and make sure your pet's water is never frozen.
            • Clean up all antifreeze spills. One lick of the sweet-tasting fluid can be fatal to an animal.
            • Before starting your car's engine, knock on the hood as cats have been known to climb into engine compartments for warmth.
            • Keep an eye out for signs that your pet is experiencing hypothermia. Symptoms include a weak pulse, dilated pupils, decreased heart rate, extreme shivering, pale or blue mucous membranes, body temperature below 95 degrees, stupor and unconsciousness.