Freeze Nap - Guess Who’s Sleeping?

Regular hibernation not cool enough for you? Try this  Wood frogs are one of a number of species that literally freeze for the winter. As temperatures drop, ice forms around its organs and cells, while its liver pumps out glucose to keep it from dehydrating and dying. Come spring, it warms up and moves on with life. —nps.gov

You read it first in this week’s The Factory in Guide magazine. 

Many creatures hibernate during the winter months. But did you know there are creatures that actually freeze during the winter and then thaw again in the spring?! That’s right! While humans would die if we were to freeze, creatures like the Wood Frog, Arctic Wooly Bear Caterpillar, Alligator, Painted Turtle Hatchling, Iguana and Darkling Beetle all freeze in some form during the harsh winter months.

The Wood Frog will get all snug and cozy amid the leafy floor of the woods to prepare for its freeze nap. “At the beginning of winter, ice quickly fills the Wood Frog’s abdominal cavity and encases the internal organs. Ice crystals form between layers of skin and muscle. The eyes turn white because the lens freezes.”  About 65% of the water in its body turns to ice.

“At the same time, the Wood Frog’s liver produces large amounts of glucose that flushes into every cell in its body. This syrupy sugar solution prevents the cells from freezing and binds the water molecules inside the cells to prevent dehydration. In spring, the frog thaws from the inside outward. First the heart starts beating, then the brain activates, and finally the legs move.” Scientists are still not sure how the heart starts beating again on its own.

“The Arctic Wooly Bear can last in the polar heights of the Arctic Circle, Greenland, and Canada because it can alternate between feeding, freezing, and thawing. According to EarthArchives.org, there is sugar in the blood of Arctic wooly bears that functions like antifreeze and safeguards the cells in frozen temperatures.”

For the Alligator, when ice starts to form, he just sticks his snout up to the water’s surface and slowly breathes as the ice forms around him. All his systems slow way down and he won’t move until the weather warms back up. 

The Painted Turtle Hatchlings will adapt in the cold,  and as their energy needs drop their metabolic rate will slow.  While the Iguana will slow and freeze up when temperatures get below 40 - 50 degrees F, falling out of trees. When the weather warms they will come around again.

The Darkling Beetle - “Unlike other animals and organisms that make use of proteins as antifreeze agents, this Darkling Beetle creates a sugar-based antifreeze known as xylomannan. Coupled with the aid of oily combinations, this antifreeze stops ice from producing in the cells of the beetle.”