As the days become chillier, many of us retreat into our warm, cozy homes to laze around and sleep – and it turns out that snakes do something similar.
Snakes in temperate regions of the country are particularly vulnerable to cold temperatures. This is because the reptiles are cold-blooded, or ectothermic, meaning that the temperature of their blood changes as the temperature of their environment changes. It's why snakes spend enormous amounts of time basking in the sun.
If the temperature in a snake’s habitat plummets, then the snake’s blood and body temperatures will drop, as well. This may cause the snake to freeze to death, if temperatures drop too low.
To survive the cold temperatures of winter, many snakes find certain places to call home and fall into a deep sleep called "brumation."
The deep sleep
Brumation refers to the "deep sleep" that snakes and other reptiles often undergo during the winter. It involves a low body temperature and the slowing down of their heart and respiratory rates, according to state herpetologist with the Virginia Department of Wildlife Resources J.D. Kleopfer.
This may sound much like hibernation, in which an animal eats enough to last them through their winter sleep. Brumation, however, involves an animal no longer eating leading up to winter. Kleopfer said this is due to the reptiles' inability to metabolize their food during brumation.
Whereas hibernating bears may pack on extra pounds immediately before winter, brumating snakes do not.
Some snake species brumate for the entire winter, while others, such as garter snakes and cottonmouths (also known as "water moccasins"), are more cold-tolerant and may awaken from their slumber to sun themselves on warmer winter days.
Searching for a spot to sleep
Snakes choose a variety of places for their winter slumber. According to Kleopfer, the locations are always underground and just below the frost line, a depth in the soil where they are safe from freezing. This allows the snakes to survive, even as temperatures at the surface drop below freezing.
Snakes may burrow underneath a pile of leaf litter or a rotting log or tree, or find a spot in a south-facing rocky crevice. They may also find large cavities in the soil underneath tree stumps. Sometimes, the reptiles may find their way into human habitats during winter.
"It’s not uncommon to find snakes sometimes in people's cellars, especially older houses that have stone foundations," Kleopfer said.
While some snakes undergo brumation alone, others may join other snakes when the temperatures drop. Kleopfer noted exceptional examples, such as thousands of rattlesnakes found in the same den in Colorado and thousands of garter snakes found together in Manitoba, Canada.
Dealing with slithering neighbors
For people concerned about finding snakes underneath their home, Kleopfer recommended hiring a reputable snake remover or having a professional seal any crevices in your home's foundation.
He also offered a word of advice regarding chemical snake repellents.
"Don't be sold on what I call proverbial snake oil," he said. "Don't be thinking that you can go out and get these snake repellents, these chemical, granular things that you can put out there – none of that stuff works."
Kleopfer also noted the ecological benefit of snakes, such as helping control rodent populations, which in turn helps control the spread of Lyme disease. Snakes may also contribute to medical science, as snake venom is being researched in the treatments of cancer and other maladies.
"I always have four simple words when dealing with snakes, and that's 'Just leave them alone,'" Kleopfer said. "They're not going to bother you, they're not going to chase you, and if you go your way, they'll go their way."