You’ll want to keep an eye out for squirrels that mess up your yard, wreck your home, or threaten local wildlife — especially invasive species like gray squirrels. Any squirrel that chews wiring, strips bark, or raids feeders can cause headaches. Bad squirrels are the ones that damage property, spread disease, or push out native species.
This post explains how squirrels can become a real problem in gardens and homes. I’ll show you what damage to watch for and help you spot which species usually cause the most trouble.
How Squirrels Can Be Problematic
Squirrels chew, dig, and nest in places you care about. They carry diseases, damage wiring, and ruin plants or bulbs in your yard.
Common Behaviors That Cause Issues
Squirrels gnaw constantly to keep their teeth in check. They’ll chew wood, plastic, and electrical wires, which can create fire hazards and leave you with costly repairs.
You’ll see them digging and hiding food. They make holes in lawns and potted soil to bury nuts. That digging can uproot bulbs and leave your lawn looking patchy.
Squirrels sneak into attics and walls to build nests. Once inside, they tear up insulation and leave droppings and urine. That mess lowers your insulation’s effectiveness and can cause odors and higher heating or cooling bills.
Dangers to Humans and Pets
Squirrels aren’t usually aggressive, but they’ll bite or scratch if you corner them. A bite might need medical care and could get infected. If you’re bitten, clean the wound and talk to a doctor if you’re unsure about the squirrel’s health.
They sometimes carry bacteria or parasites that affect people and pets. Touching contaminated soil or droppings can spread germs. Try to keep pets away from squirrel nests and always wash your hands after handling soil or bird feeders.
If you spot a sick or oddly tame squirrel, don’t touch it. Instead, call animal control or a wildlife rehabber to check for disease and handle the animal safely.
Property and Garden Damage
Squirrels strip bark from young trees and girdle branches, which can kill fruit or ornamental trees. They chew fruit, bulbs, and seedlings, so you’ll probably lose some plants in your garden or flower beds.
Inside homes, squirrels chew attic wiring, decking, and vents. Check attics, eaves, and rafters if you notice squirrel activity. Seal gaps bigger than a quarter-inch with metal flashing or hardware cloth to keep them out.
To protect feeders and plants, try baffles, heavy-duty wire mesh, or raised beds with covers. Replace any frayed wires and fix insulation quickly to reduce fire and pest risks. If squirrels keep coming back, you might want to call a licensed pest control or wildlife removal expert.
Identifying Bad Squirrels by Species
Some squirrels really do harm native wildlife, damage property, or carry nasty diseases. It helps to know which species cause the worst problems, how to tell them apart, and what you can actually do to cut down on the damage.
Invasive Species and Their Impact
Invasive squirrels, like the Eastern gray squirrel, push out native species for food and nesting spots. They also spread diseases like squirrelpox, which can wipe out native red squirrels in places where gray squirrels have taken over.
If you live where non-native squirrels have moved in, you’ll probably notice their numbers jump and see fewer red squirrels in the woods nearby.
You might spot invasion signs: freshly gnawed tree trunks, new leaf nests, and lots of raids on bird feeders. Land managers fight the spread with trapping, changing habitats, and public education. Planting conifers and not feeding squirrels on purpose can help red squirrels hang on where they’re struggling with invasive competition.
Want more on how gray squirrels displace natives? Check out this page about invasive squirrel impacts (https://petshun.com/article/which-squirrels-are-bad).
Fox Squirrel vs. Red Squirrel
Fox squirrels are bigger and heavier, and they handle city life better than red squirrels. Red squirrels are smaller, more reddish, and rely on conifer seeds. If you spot a big, brownish squirrel in a park or yard, it’s probably a fox squirrel. See a small, quick reddish squirrel in pine woods? That’s likely a red squirrel.
Here’s what matters: fox and gray squirrels can outcompete red squirrels for food and nesting spots. Red squirrels lose out when larger species move in or bring in new diseases. If you want to help red squirrels, plant hazel, spruce, or pine, and avoid feeding bigger squirrel species that might attract them to your property.
Dealing With Squirrel Infestations
When squirrels move into your attic or start chewing on wiring, you’ve got to act fast. If you wait, the damage just gets worse.
Take a close look at the size of the holes and the tracks they leave behind—fox and gray squirrels usually chew out baseball-sized openings. If you spot babies, don’t try to handle things yourself. Removing young squirrels can lead to the mother abandoning them, or even get you tangled up in legal trouble.
Honestly, it’s best to call a licensed wildlife control operator. They’ll check things out, remove the animals in a humane way, and set up one-way exclusion devices so the squirrels can’t sneak back in.
Once they’re gone, you should seal every possible entry point. Use sturdy stuff like metal flashing or hardware cloth. Also, trim back any tree branches that make it easy for squirrels to hop onto your roof.
Want to keep them away? Try squirrel-proof bird feeders, and don’t leave pet food outside. If you’re not sure what’s allowed in your area, you can find more details at the Oregon State University pest problems site: https://solvepestproblems.oregonstate.edu/rodents-wildlife/squirrels.
