If you’re hearing scratching and scurrying in your attic at night, it’s probably not the gray or red squirrels you see in your yard. Those species are active during the day. Nighttime squirrel sounds almost always come from flying squirrels, which are the most nocturnal of all tree squirrels and frequently move into attics without homeowners ever seeing them.
Why Nighttime Rules Out Most Squirrels
Gray squirrels, red squirrels, and fox squirrels follow the sun. They leave their nests at dawn, forage during daylight, and return before dark. If your attic noises happen between sunrise and sunset, one of these species is the likely culprit. But sounds that start after sundown and continue through the night point to a different animal entirely.
Flying squirrels leave their nests soon after sundown to forage and return before sunrise. That schedule puts their most active periods right when you’re falling asleep and right before your alarm goes off, which is why so many people first notice the problem in bed.
What Flying Squirrels Sound Like
The typical pattern is a soft thud followed by rapid scurrying along the roof or soffit. Flying squirrels glide from nearby trees and land on the roof, which creates that initial impact sound. Then you’ll hear fast, light skittering across the ceiling as they move around. The movement is quicker and softer than what you’d hear from a gray squirrel, which tends to produce heavier, more deliberate thumping during the day.
One key detail: flying squirrels almost never travel alone. They are highly social and congregate in groups, sometimes large ones. Wildlife professionals report catching 10 or more from a single home. So if the scurrying sounds like multiple animals chasing each other overhead, that’s consistent with a flying squirrel colony rather than a lone intruder.
How to Tell It’s Not Mice, Rats, or Raccoons
Several animals make noise in attics at night, and they can sound surprisingly similar. Here’s how to narrow it down:
- Mice produce soft, quick skittering without any thumping. Their footsteps are lighter and more delicate than flying squirrels, and their activity often increases when the house gets quiet. Mouse droppings are tiny, dark pellets. Flying squirrel droppings look similar but tend to accumulate in larger quantities because of the group sizes involved.
- Rats are noisier chewers. You’ll hear grinding sounds from gnawing on woodwork, and their movements are heavier than mice but lack the distinctive thud-then-scurry pattern of a flying squirrel landing on the roof.
- Raccoons are the heaviest attic invaders. They create loud thumping, and you may hear soft mewing, chirring, or snarling vocalizations. If it sounds like a person walking around up there, think raccoon. Flying squirrels are far lighter and faster.
- Bats produce soft scratching inside walls rather than overhead scurrying, often accompanied by faint high-pitched, metallic sounds. Their activity peaks at sunup and sundown as they crawl slowly to and from exit points, rather than running across open attic space.
How Flying Squirrels Get In
Flying squirrels can squeeze through remarkably small gaps. Entry points as small as 7/8 of an inch are enough, and pregnant females can fit through holes just 1.25 inches in diameter. For comparison, gray squirrels need roughly a two-inch opening. This means flying squirrels exploit gaps that most homeowners would never suspect, including small cracks along the roofline, gaps around soffit vents, and openings where utility lines enter the house.
Their nests inside attics are built from whatever soft material is available. Shredded insulation is a favorite, along with gnawed bits of wood, leaves, and fur. If you inspect your attic and find insulation that’s been torn apart or pulled into piles, that’s a strong indicator. You may also notice a persistent bad odor from accumulated urine and feces, especially once a colony has been established for a while.
Confirming the Problem
Because flying squirrels are nocturnal and small (roughly the size of a chipmunk), most people never actually see them. Physical evidence is usually how you confirm their presence. Look for small, dark droppings that resemble mouse droppings but are concentrated in larger amounts. Check for gnaw marks on wood framing and, more importantly, on electrical wiring. Chewed wiring is one of the more serious risks of any squirrel infestation because it creates a fire hazard inside walls and ceilings.
Another confirmation method is to go outside at dusk and watch your roofline. Flying squirrels glide from trees to rooftops, and on a clear evening you can sometimes spot their silhouettes launching from a nearby branch. A gap of 20 to 60 feet between a tall tree and your roof is well within their gliding range.
Timing Matters for Removal
Flying squirrels typically breed in spring, with young born anywhere from May through early July depending on the climate. Newborns are hairless with closed eyes and ears, and they develop slowly compared to other small mammals. Their eyes don’t open until about 25 days, and they nurse for 60 to 70 days. That means dependent, immobile babies may be in your attic from roughly May through September.
This matters because exclusion methods (sealing entry points to let animals leave but not return) can trap flightless young inside the attic, where they’ll die. If you’re hearing nighttime sounds during late spring or summer, a wildlife professional will typically check for a nest with young before sealing anything up. Late fall and winter are generally the simplest times to address the problem, since any young from the previous season are old enough to leave on their own.
Preventing Reentry
Once the animals are out, sealing every potential entry point is the only lasting fix. Because flying squirrels can use gaps under an inch wide, this means inspecting the entire roofline, soffit, fascia boards, gable vents, and any point where different building materials meet. Hardware cloth or metal flashing works better than foam or caulk, since squirrels can chew through softer materials.
Trimming tree branches that overhang or come within gliding distance of the roof also reduces the chance of a new colony arriving. Flying squirrels are strong gliders, so branches don’t need to touch the house to be a problem. Cutting back limbs to at least 8 to 10 feet from the roofline makes the approach significantly harder for them.