Marmota monax

Groundhogs are so famous, they have a day named after them on February 2. Every year on Groundhog Day, a groundhog named Punxsutawney Phil comes out of his burrow. According to tradition, if he sees his shadow, there will be six more weeks of winter. Otherwise spring will arrive early. But how much do you really know about groundhogs?

Groundhog or woodchuck

Also called woodchucks and whistle pigs, groundhogs are a species of marmot and a kind of rodent. They’re called whistle pigs because they let out a shrill whistle when they sense danger.

Groundhogs are 42-68 cm (16-27 in.) long and weigh anywhere between 2-6 kg (4-14 lb.). Their weight fluctuates quite a bit depending on the season.

Groundhogs live in North America as far south as Alabama and as far north as Alaska! They often make their homes at the edge of woodlands, near streams, along fences, by roadways, or in backyards.

With short, powerful legs, groundhogs are excellent diggers. They dig expansive burrows that range in size from 2.5-20 m (8-66 ft.) long. Their burrows may have several entrances, but often, the main entrance is by a stump or rock. Inside the burrow are many tunnels and chambers, including bathrooms! In the main chamber, a groundhog will make a nest of dried plants.

Groundhogs have other skills besides digging. They can climb trees, and they can even swim!

Groundhog or woodchuck

In the spring and summer, groundhogs consume a massive amount of food so they can build up a nice thick layer of fat. They eat at least half a kilogram (1 lb.) of vegetation per day! Luckily, they have teeth that never stop growing to keep up with the constant wear and tear.

In late October, groundhogs go down to their burrows to hibernate for the winter. Their heart rate slows from 80 beats per minute to 5. Their body temperature drops from 37°C to 3°C (99°F to 37°F). That’s barely above freezing! Because their metabolism slows down so much, groundhogs can go without food or water for months.

Though groundhogs are not keystone species, they do help other animals and plants thrive. For example, many other animals take shelter in groundhog burrows, including skunks, foxes, weasels, toads, mice, snakes, opossums, and rabbits. In addition, their tunneling helps aerate and mix the soil. This improves the soil quality and allows it to absorb more water.

What Groundhogs Eat

Groundhogs eat grass, plants, fruit, flowers, and tree bark. Sometimes they climb trees in order to reach apples and pawpaws (a kind of fruit).

Groundhog Reproduction

Groundhogs are generally solitary animals and only get together to mate. In early February, males leave their burrows to scope out where the female burrows are. Then they go back to sleep for a month. Mating starts in early March. After a gestation period of about a month, the female gives birth to a litter of 2-9 pups.

The pups are born hairless and blind. But after four weeks, they open their eyes. They stay with their mother for several months before leaving the burrow to dig homes of their own.

Young groundhogs

Groundhogs live about 2-3 years in the wild. Predators include dogs, coyotes, and foxes. Though not exceptionally fast, topping out at speeds up to 13 km/h (8 mph), groundhogs can escape predators by scurrying into their burrows and fighting them from there.

Conservation Status

According to the IUCN Redlist, groundhogs are a species of least concern and their population is stable.

More Groundhog Resources

Blog Posts about the Groundhog

About the Author

Abi Cushman is a contributing editor of Animal Fact Guide and My House Rabbit. When she's not writing about weird animal facts, Abi writes and illustrates funny books for kids. Her picture books, Soaked! and Animals Go Vroom!, are available now from Viking Children's Books.

To learn more and to download free activity sheets, visit Follow her on Twitter at @AbiCushman and on Instagram at @Abi.Cushman.