If you’re hearing daytime scratching overhead or finding shredded insulation in attic corners, you likely have a squirrel nest up there. Squirrels are one of the most common attic invaders, and they cause real damage: chewed wiring, contaminated insulation, and structural holes that grow worse every week they stay. The good news is that squirrel problems are solvable, but the approach matters, especially if babies are involved.
How to Tell You Have a Squirrel Nest
The biggest giveaway is noise during the day. Unlike rats and mice, which are mostly active at night, squirrels are daytime animals. You’ll hear scampering and scratching in the morning and late afternoon as they leave and return. Thumping or rolling sounds often mean they’re dropping nuts or leaping between beams. Chewing sounds are common too, since squirrels’ teeth grow continuously and they gnaw constantly to keep them filed down.
The nest itself is usually tucked into a dark corner or cranny. Squirrels build them from dry leaves, twigs, and other outdoor material they carry inside. They also shred whatever they find in the attic: paper, fabric from stored clothing, cardboard. Loose insulation is a favorite nesting material. If you see a pile of insulation gathered in an isolated spot, that’s almost certainly a nest site. The nests vary in size, but they’re unmistakable once you know what to look for: a messy, rounded pile of mixed materials in a sheltered spot.
Other signs include droppings (small, dark pellets roughly the size of a grain of rice), visible chew marks on wood framing or wiring, and one or more holes on the exterior of your roof or soffits. Squirrels can squeeze through openings as small as about 1.5 inches, and they’ll widen smaller gaps by chewing.
Why Squirrels Choose Your Attic
Attics mimic a tree cavity: warm, dry, elevated, and protected from predators. Female squirrels are especially drawn to attics when they’re pregnant, since attics offer better insulation than an outdoor leaf nest. The breeding season runs roughly from late December through late August, with young born as early as mid-February and as late as mid-November depending on climate and food supply. Grey squirrels carry their young for about 42 to 45 days before giving birth.
This means that from roughly February through October, any squirrel nest in your attic could contain babies. That timing matters enormously for removal, as we’ll cover below.
The Real Risks of Leaving Them
Fire and Electrical Damage
Chewed wiring is the most serious hazard. Because squirrels must constantly gnaw to wear down their teeth, electrical cables are a frequent target. Exposed or damaged wiring can overheat, spark, trip breakers, or start a fire. Wildlife-related damage causes roughly 13 million Americans to lose power every year, and squirrels are among the top culprits. One fire safety company reported mitigating over 50 squirrel-caused fire hazards in a single year.
Health Hazards
Squirrel droppings and urine accumulate fast, and the contamination is more than just unpleasant. Squirrels can carry salmonella bacteria in their droppings, and disturbing contaminated areas during cleaning is a common way people get exposed. Symptoms include diarrhea, fever, and abdominal cramps, typically within 12 to 72 hours. Leptospirosis spreads through contact with infected urine or contaminated surfaces and can cause fever, muscle aches, vomiting, and jaundice.
Squirrels also carry ticks and fleas into your attic. Those parasites drop off into insulation and crawl spaces, where they can reach pets or people. Ticks that feed on squirrels may carry Lyme disease or Rocky Mountain spotted fever. Ringworm, a fungal infection, can spread through contact with contaminated insulation or nesting materials, leaving itchy, circular rashes. While squirrels can technically carry hantavirus, transmission to humans from squirrels is rare.
Structural Damage
Beyond wiring, squirrels chew through wood framing, roof decking, and plastic plumbing vents. They compress and soil insulation, reducing its effectiveness. Water damage often follows, since entry holes let rain in. The longer squirrels stay, the more expensive the repair.
How to Remove Squirrels Safely
The standard approach is exclusion, not trapping. Exclusion means letting squirrels leave on their own and preventing them from getting back in. It’s more effective and less legally complicated than trapping.
Start by inspecting your roofline, soffits, gable vents, and any point where different building materials meet. Identify every entry hole. Squirrels typically have one main entrance and one or more secondary openings. Seal all the secondary holes with half-inch hardware cloth (wire mesh with half-inch openings), which is the standard gauge for blocking squirrels. Screw or bolt the mesh securely, since squirrels will test it.
On the main entry point, install a one-way exclusion door. This is either a wire funnel or a spring-loaded flap that lets a squirrel push out but prevents re-entry. The funnel version uses flexible wire mesh shaped into a tube. When the squirrel pushes through, the wire ends close behind it. The spring-loaded version works like a pet door that only opens outward. Either type needs to be securely mounted to the building with screws, bolts, or sealant depending on the surface. Leave the one-way door in place for at least a few days to make sure all squirrels have exited before sealing the final hole.
What to Do If Babies Are Present
This is the most important detail people miss. If you seal the entry holes while baby squirrels are still inside, the mother will tear new holes trying to reach them, or the babies will die in your attic. Baby squirrels don’t open their eyes until about four weeks old. They start exploring outside the nest around six weeks and aren’t fully weaned until ten weeks.
If you find babies, you have two options. The first is to wait. Let the mother continue raising them until they’re mobile enough (around six to eight weeks) to leave through a one-way door on their own. The second option is to carefully place the babies in a box near the base of the tree closest to your home, with a warm sock filled with uncooked rice (microwaved for 20 to 30 seconds) wrapped in a towel beside them. The mother will often retrieve them within six to eight hours. Reheat the rice sock every two hours. Don’t give the babies food or water, and don’t leave them outside overnight. If the mother hasn’t returned by sunset, bring them in and try again the next morning. If she still doesn’t come, contact a wildlife rehabilitator.
If a baby squirrel appears injured, cold, wet, or is covered in tiny white specks that look like grains of rice (fly eggs), it needs professional help immediately.
Legal Considerations for Trapping
Wildlife removal laws vary by state and sometimes by species. In New York, for example, it’s illegal to live-trap an animal and relocate it off your property, even to a park or public land. Relocation can spread diseases like rabies and Lyme and causes significant stress to the animal. Grey and fox squirrels in New York require a permit from the state’s Department of Environmental Conservation to remove, while red and flying squirrels can be taken without one when they’re damaging property. If a squirrel is taken outside of hunting season, the carcass must be buried or cremated immediately.
Many states have similar restrictions. If you’re unsure about local rules, a licensed nuisance wildlife control operator can handle the removal legally. This is especially worth considering if babies are involved or if the entry points are in hard-to-reach spots on the roof.
Cleaning Up After Removal
Once every squirrel is out and every hole is sealed, the attic needs decontamination. Squirrel droppings, urine-soaked insulation, and nesting debris carry bacteria, fungal spores, and parasites. Don’t sweep or vacuum dry droppings, which can send pathogens airborne. Mist the area with a disinfectant solution first, then clean while wearing gloves and a respirator rated for particulates.
Insulation that’s been compressed, shredded, soiled, or nested in is essentially useless. It can’t insulate properly, and it harbors contaminants. Replacing damaged insulation restores your attic’s energy efficiency and eliminates lingering health risks. If the damage is extensive, professional attic restoration services will remove contaminated material, sanitize surfaces, and install new insulation. For smaller infestations, you may be able to handle the cleanup yourself with proper protective equipment and thorough disinfection.
Inspect any visible wiring for chew marks before turning the project over to “done.” If you see exposed copper or frayed sheathing on electrical cables, have an electrician assess the damage before it becomes a fire risk.