People mix up groundhogs, beavers, and muskrats all the time, especially when one of them shows up near a pond or a creek. They are all rodents, but they live differently, damage things differently, and need to be handled differently. The fastest way to tell them apart is the tail. Everything else follows from there. For more, see How to Find Groundhog Burrows Around Your Property.
The tail tells you almost everything
- A beaver has a broad, flat, paddle-shaped tail. It is hairless and looks like it belongs on a boat oar. If the animal is in the water and slaps its tail, it is a beaver.
- A muskrat has a thin, round-ish tail, also mostly hairless, that it uses like a rudder when it swims.
- A groundhog has a short, bushy, furry tail. If the tail is furry, it is a groundhog, full stop.
If you only remember one thing from this page, remember that.
Groundhog. Photo: Cephas, CC BY-SA 3.0
North American beaver
Muskrat. Photo: Cephas, CC BY-SA 3.0
Size and body
Beavers are the biggest, full grown ones can be 40 pounds or more, and they are the largest rodent in North America. Groundhogs are mid-sized and stocky, roughly the size of a small dog. Muskrats are the smallest of the three, a couple of pounds, and people mistake them for big rats.
Where they live and how they act
Groundhogs are land animals. They dig burrows in fields, fence lines, and under sheds, and they hibernate through winter. They eat grass and garden plants, and their damage is all about digging.
Beavers are water animals. They build dams and lodges, and they chew down trees, leaving pointed, hourglass-shaped stumps. That tree chewing is the signature beaver sign.
Muskrats are semi-aquatic. They live in marshes and ponds, build small lodges out of cattails, and burrow into banks. They do not cut down trees or build dams. Their damage is bank burrowing and erosion.
One field tip that helps near water: if the animal is swimming, it is not a groundhog. A groundhog might wade, but it is not out there cruising a pond the way a beaver or muskrat does.
How to tell which one is causing the damage
- Chewed trees with pointed stumps, a dam, or a lodge of sticks in a pond: beaver.
- Burrows in a bank at the waterline with underwater entrances, or small cattail lodges: muskrat.
- A burrow with a dirt mound in the ground, near a garden or under a shed, no water required: groundhog.
What to do about each
Groundhogs: live trapping, exclusion fencing with an underground barrier, and clearing cover. Beavers: this one usually needs a professional, since trapping, dam work, and flow devices often require permits. Muskrats: trapping plus bank protection with mesh or riprap, and cutting back aquatic plants to make the spot less inviting.
Frequently Asked Questions
The tail. Groundhogs have a bushy, furry tail and live on land in burrows. Muskrats have a thin, mostly hairless tail and live in the water. Groundhogs are also bigger and hibernate.
No. A beaver is much larger, has a flat paddle tail, lives in water, and chews down trees. A groundhog is mid-sized, has a furry tail, digs burrows on land, and hibernates. Different animals, different problems.
No. Muskrats build small lodges out of cattails and other plants, but they do not dam streams. Only beavers do that. Muskrat damage is burrowing into banks and levees.
Chewed trees and a dam mean beaver. Burrows in the bank and cattail lodges mean muskrat. A burrow in the ground near the pond, not in the bank itself, points to a groundhog.
