Flying squirrels are nocturnal, so they typically do leave the attic at night to forage, not during the day. During daylight hours, flying squirrels are sleeping in their nest, which means your attic is occupied precisely when you might assume it’s empty. This matters if you’re planning to seal entry points, because doing so during the day could trap the animals inside.
When Flying Squirrels Are Active
Flying squirrels operate on the opposite schedule of the gray squirrels most people are familiar with. Gray squirrels are active in the morning and around dusk, which is why homeowners with gray squirrels hear noises at sunrise or during the day. Flying squirrels leave the nest after dark and return before dawn. They stay active all year and do not hibernate, though they may sleep for several consecutive days during cold winter stretches.
If you’re hearing sounds in your attic, the timing tells you a lot. A fast tapping or light scurrying sound that travels across the ceiling at night, sometimes described as a finger-drumming pattern, points to flying squirrels. Morning or daytime scratching and running sounds are more likely gray squirrels. Flying squirrels also tend to live in groups, so you may hear repeated movement from multiple animals rather than a single one.
Why Daytime Sealing Is Risky
Because flying squirrels spend the day sleeping inside the attic, sealing entry holes during daylight hours is one of the most common mistakes homeowners make. You’d be locking the animals in rather than out. Trapped flying squirrels will chew aggressively through walls, ceilings, and any material softer than their teeth to escape or find food, causing far more damage than they would otherwise.
The situation gets worse during breeding season. Northern flying squirrels can breed from March through late June, with young born roughly 37 days later. The babies nurse for 60 to 70 days and aren’t fully grown until around 240 days old. Southern flying squirrels often have a second litter in late summer or early fall. Sealing adults out while young are still inside creates a genuinely bad outcome: babies that can’t survive on their own and a desperate mother trying to chew back in. Wildlife professionals consider this one of the worst scenarios they get called to handle.
How They Get In
Flying squirrels can squeeze through openings as small as 7/8 of an inch. Pregnant females pass through holes just 1.25 inches in diameter. If an existing gap is too small, they’ll chew it wider, as long as the surrounding material is softer than their teeth. This means wood, vinyl, plastic ridge cap vents, and foam plugs are all vulnerable. Ten or more entry points on a single home are common, because flying squirrels actively explore and develop as many access routes as possible.
Ridge cap vents are a frequent weak spot, especially newer designs made of plastic and capped with shingle material. Once a flying squirrel chews through the plastic grating on the side, it can crawl through the ventilation slot underneath. Any lasting repair needs to use materials harder than their teeth: steel mesh, metal plate, or masonry.
Signs You Have Flying Squirrels
Beyond nighttime sounds, there are a few physical clues. Flying squirrels create “latrines,” which are concentrated clusters of droppings on attic insulation rather than droppings scattered randomly. You may also hear gnawing sounds if the animals are modifying the interior of walls or ceilings. Because they’re small and nocturnal, many homeowners live with a flying squirrel colony for months before realizing something is up there. The noise is lighter and faster than what a gray squirrel or raccoon produces, so it’s easy to dismiss.
Getting Them Out Safely
The standard approach for flying squirrels is a one-way exclusion door installed over the primary entry point, with all other entry points sealed using steel mesh or metal flashing. The one-way door lets the squirrels leave at night on their normal foraging schedule but prevents them from re-entering. This works best on solid structures like brick or block exteriors where the animals can’t simply chew a new hole next to the sealed one.
Timing matters in two ways. First, exclusion should happen at night or in the evening, aligned with when the squirrels actually leave. Second, avoid exclusion during likely nesting periods (roughly April through August, and again in late summer or fall if a second litter is possible) unless you’ve confirmed no young are present inside. Wildlife removal professionals stress that squirrels of all types are among the most persistent animals at trying to re-enter a structure, and flying squirrels’ small size and numerous entry points make them especially challenging. A thorough inspection of every potential gap, crack, and vent on the roofline is essential before any exclusion work begins.