In winter months in colder climates, snakes go into either hibernation-like dormant state that’s technically called brumation. They use cues such as number of hours of daylight, humidity, and barometric pressure to know when it’s time to enter snake hibernation.
Snake hibernation is a state of deep sleep where an animal conserves its energy by slowing down the metabolic rate, heart rate, and breathing rate. Only snakes in cold climates hibernate. They will dig into warm dens, logs and burrows to survive the long, cold winter.
Let’s take a look at all your questions about snake hibernation (aka brumation!).
Where do Snakes Hibernate? (The Hibernacula)
Snakes choose to hibernate at a warm place that has the least chances of getting affected by wind or rain. Caves, tree stumps, woodpiles, storage spaces, basements, garages, and open pipes are excellent places for them to settle down for the winter.
The places where snakes hibernate are called hibernacula and include dens and burrows made by other animals such as rodents, squirrels, and other snakes.
A minority of snake species can dig hibernacula for themselves while others use the one dig by others. The Northern Pine Snake is one of the few who dig their own hibernacula. A snake may use the same hibernacula for many years and different seasons.
Often snakes share dens with other snakes to share the body heat for better survival during winters. The den may consist of babies, males, and females of the same or even different species.
Do Snakes Hibernate in Houses?
Snakes can hibernate inside a house, including in garages, attics, under plumbing, and inside the house’s foundations.
This is because houses are often warm places where the snake can escape freezing temperatures. If you live in an area where there are wild snakes, there’s a chance there could be a snake under your house’s foundations for the winter.
This all depends on whether the conditions under the house are right for the creature. They seek out spaces that are dark, damp, and don’t drip below freezing temperature.
Sometimes, people will find a hibernating snake and think it’s dead. The snake will be cold to touch, have dilated pupils, and could even have loose skin because it’s lost weight over the winter.
But, when the snake is laid out in the sun for 30 minutes, it could wake up and slither away.
Why do Snakes Hibernate?
As cold blooded animals, snakes usually rely on the warmth of the sun to stay warm. During winters when the temperature gets too low, they cannot effectively control their body temperature.
To survive the winter, snakes shut down their systems and become dormant. During this period of inactivity, they stop feeding, and may not defecate or move for weeks on end. To stay hydrated they absorb water through their skin. This helps them to get through the winter.
When do Snakes Hibernate?
The hibernation (aka brumation) period for snakes depends on their climate, but in colder areas, they enter hibernation in late fall and emerge in spring time.
Snakes in warmer climates, including in areas of India and Australia, are less likely to hibernate, and stay active throughout the winter months.
There is a lot of research into snake hibernation in northern parts of the United States and Canada because in this climate winter temperatures drop below freezing level. For snakes like the the northern pine snake, hibernation begins anytime in September to December and continues until March or April when the average daytime temperature is about 60 F.
Entering the den is referred to as ingress while exiting the den is called egress.
Do Snakes Hibernate in Groups?
Some snake species hibernate in groups, while other hibernate alone.
Snakes are often solitary creatures. But when it comes time for hibernation, hanging out in a group seems to help them survive the winter. They can conserve body heat when they sleep together as a pack.
Creepy sake pits can be filled with thousands of snakes all hibernating together for the long winter. In fact, the town of Narcisse in Manitoba attracts up to 70,000 hibernating garter snakes per year. Near the town, there are large underground limestone caverns which regulate the temperature in winter so it never drops below freezing.
Here’s some creepy footage of them emerging!
Which Species of Snakes are Known to Hibernate?
Do Copperhead Snakes Hibernate?
Copperhead snakes prefer woody and damp habitats near water ponds, lakes, and rivers. They hibernate in rugged areas which are close to hills and receive sunlight. Den spots for copperheads include stonewalls, caves, logs, and holes.
They often share their den with other snakes and even different species such as black racers and rattlers. They hibernate in the fall and come out in early April.
Copperhead snakes are poisonous and are abundantly found in South America. Their coloration varies from basic brown to beige. This coloration helps them in making camouflaging when surrounded by foliage.
Do Garter Snakes Hibernate?
Common garter snakes like to hibernate in rock piles, stumps, crayfish burrows, and rodent burrows. They are even found in basements to spend the winter. In the hibernaculum, they hibernate with hundreds of other garter snakes and coil around each other to keep their bodies warm at a minimum temp.
Common garter snakes are non-venomous and are 3 feet in length. They are found throughout the US and along the Gulf of Mexico. Their hibernation period starts from late October to March or early April. Den spots for common garter snakes include natural burros or cavities.
Do Grass Snakes Hibernate?
Grass snakes hibernate between November and March. They are mostly found in wetland habitats, dry grasslands, gardens, and ponds. The hibernating areas include fallen trees, rabbit warrens, and compost heaps.
They are abundant in England and Wales. Typically, they are greenish in color and have a characteristic yellow and black collar.
Do Vipers Hibernate?
Common European vipers (aka Adders) hibernate from October and March in sheltered and dry spots such as borrows in the fallen trees and of an old rodent.
Vipers are venomous snakes found across Britain in open habitats such as moorland and heathlands.
Do Corn Snakes Hibernate?
Corn snakes become less active during the fall and winter months and brumate under loose bark, rocks, debris, and beneath logs.
They are seen in wooded grooves, meadowlands, rocky hillsides, and barns. They have a checkboard pattern on the belly with alternating rows of white and black spots.
Do Milk Snakes Hibernate?
Milk snakes brumate from November to mid-April in communal dens such as in the burrows and rock crevices. They may share their dens with rattlesnakes.
Milk snakes are non-venomous and are found in a variety of habitats including woodlands, prairies, rocky hillsides, and grasslands.
They are active at night and are rarely seen during the day.
Under certain circumstances, Garter snakes and viper snakes can also undergo brumation instead of hibernation to survive through extreme weather conditions.
What is Snake Brumation?
Hibernation of cold-blooded animals like snakes is called brumation, while mammals technically hibernate.
The difference between hibernation and brumation is that during brumation snakes can wake up to drink, go to the bathroom, and bask in the sun. But, just like hibernation, they still spend most of their winter in a dormant state.
Generally, mammals like bears will go into full hibernation, while snakes go into brumation. They choose brumation rather than hibernation because they are cold-blooded animals, so they have different needs than mammals who are better at regulating their internal body temperature.
For example, these scientists, examined Timber Rattlesnakes, and found that they will occassionally emerge fom their hibernation state to bask on rocks. While there is some minimal energy expenditure that occurs when snakes wake mid-winter, these intermittent periods of activity can help the snakes make it through the winter by helping them to raise their body temperature on warm winter days.
Don’t stress too much about this terminology unless you’re an animal scientist. Even many scientists conflate the two terms.
How do Brumating Snakes React to Weather Changes?
Snakes will seek out a hibernation location that is resistant to flood and freezing but also allows for air to flow in from outside.
This often involve finding a den-like hole that is far enough below ground that the soil around the snake will not reach freezing level. Some scientists call this the ‘life zone‘.
During the cold season, if a warm spell comes, snakes may come out of brumation for some time. This allows them to venture out for foraging and sun-basking. Once the weather becomes cold again, they go back to their brumation state.
It is important for snakes to digest their food before entering a state of hibernation because the food in their digestive tract will decay and kill them. Skinny snakes are less likely to survive the brumation period.
Snakes hibernate at warm and safe places to spend period of extreme cold. Caves, tree stumps, woodpiles are excellent places for hibernation.
It allows them to reduce their body metabolism and survive with minimum energy spent. Rattle snakes, garter snakes, copperheads etc. are known to undergo hibernation.
Some snakes may undergo brumation, a state like hibernation. Snakes are not completely inactive in brumation. Corn snakes and milk snakes are prominent snake species to undergo brumation.
Snakes in cold climates hibernate between September and April depending on severity of weather. Snakes can come out of brumation if the weather becomes favorable.