Do I Have Flying Squirrels in My Attic?
Flying squirrel problems typically get mistaken for something else. Most homeowners who call about noises in the attic assume they have mice or regular squirrels, because they have never seen a flying squirrel and don’t know that they live here. Some pest control companies make the same mistake, and will spend months fruitlessly trapping for mice in a house that has a colony of flying squirrels, until the exasperated homeowner calls us for a second opinion.
This guide covers how flying squirrels live, why they get mistaken for other animals, and how to tell when it is happening in your own attic.
Flying Squirrels Are Common in Tennessee
When we tell a homeowner that they might have flying squirrels, we usually hear some version of the same question: “Do we even have those around here? I’ve never seen one.”
Most people haven’t, because a flying squirrel is a nocturnal tree squirrel. This means that under normal circumstances they only come out of the den after dark, and they spend the night up in the tree canopy. They sleep through the day inside a tree cavity, and rarely come down to the ground at all. You can live surrounded by trees for decades and never see one.
Despite how rarely they are seen, flying squirrels are common. Southern flying squirrels live across the entire eastern half of the country wherever there is mature hardwood forest, because that is where the tree cavities they den in are found, and Middle Tennessee has plenty of it.
Flying squirrels are omnivores. Though tree nuts, seeds, and fungi make up the majority of their diet, they actively hunt and consume animal matter more than is common for other squirrels. Insects, bird eggs, nestlings, and carrion all show up in their diet alongside the acorns and hickory nuts that make up the bulk of it.
One of the other unique characteristics of flying squirrels, the one from which they derive their name, is their ability to travel long distances through the air. A flying squirrel glides on a membrane of skin stretched between its wrist and ankle. The northern flying squirrel glides an average distance of about 65 feet, and the southern flying squirrel glides an average of 20 to 30 feet, though both species have been recorded gliding well over 100 feet. For this reason, trimming the branches that touch your roof does very little to stop them.
Aren’t Flying Squirrels Endangered?
Many homeowners have heard that flying squirrels are endangered, and are surprised to learn that finding them inside attics is such a widespread issue. This is because the species that is commonly found inside homes is the southern flying squirrel, which has abundant populations across Middle Tennessee.
The flying squirrel that is currently listed as endangered is the Carolina northern flying squirrel. It is a subspecies of the northern flying squirrel that lives in high elevation spruce and fir forest, generally above 4,500 feet, on a handful of mountain peaks along Tennessee’s far eastern border. Another subspecies, the West Virginia northern flying squirrel, was listed as endangered in 1985 but was delisted in 2013 when habitat restoration led to their population bouncing back.
Mice or Flying Squirrels?
The southern flying squirrel is Tennessee’s smallest tree squirrel, not much bigger than a mouse, and it only moves around after dark. They also tend to move into homes in the fall and winter, which is the same time of year mice do. So if you have been hearing noises at night and assumed you have mice, it was a reasonable assumption.
Though noise alone is not always enough to tell which animal you have, there are often differences in what you hear. Homeowners report hearing scurrying far more often with flying squirrels than with mice. Because they live in groups and are very social, multiple squirrels can sometimes be heard moving at the same time. They can be especially active and playful on nights when the weather is too harsh for them to go outside to find food. Mice are more commonly heard scratching in specific locations, and the scurrying sounds tend to be rarer.
Flying squirrels also carry nuts into the house to store them, and clients will sometimes describe hearing nuts rolling across the ceiling or falling down inside wall cavities in the middle of the night. Flying squirrels make a faint, bird-like chirping sound, but many homeowners never hear it.
Physical evidence can help as well, though it is easy to miss. Flying squirrels use a communal bathroom area, known as a latrine, so their droppings and urine collect in specific sections of the house instead of being scattered throughout the attic the way mouse droppings typically are. Many pest control technicians regularly walk past flying squirrel droppings without recognizing them. Footprints can sometimes be seen in the dust on attic ductwork, but many Middle Tennessee homes have their ductwork in the crawl space instead of the attic.
Another clue is a mouse job that isn’t working. If the traps stay empty night after night while the noise continues, something other than a mouse may be present. Sometimes a snap trap will disappear entirely. A missing trap can mean a few different things. The most common reason is that the animal that triggered the trap was not a mouse, and the trap injured but did not kill it. Oftentimes these animals panic and run off in distress. A mouse trap is not strong enough to kill a flying squirrel, but it is too strong for the squirrel to pull free of, so it runs off with the trap still clamped on and may die slowly somewhere inside the house.
Though there are other reasons a trap may disappear, such as bad trap placement and larger animals taking the carcass away to eat it, a trap disappearing is a strong sign that you are not dealing with mice. If the wrong animal turns up in a trap, or if a trap disappears, everything lethal should come out of the attic that same day. All trapping should be discontinued until a wildlife professional can assess the situation.
The “Baby Squirrel” Confusion
We often get calls from homeowners who have seen a “baby squirrel” running around inside their house. Sometimes it has happened more than once. Either they caught it and put it outside, or it disappeared before they could.
Young gray squirrels will occasionally end up in living spaces, usually by falling down a chimney flue or a wall cavity. However, this is rare, and it mostly happens during certain windows in baby season. Most commonly this is when the babies have been separated from their mother. Sometimes this is because she has been killed by a predator or car. Other times it is because a homeowner attempted to close holes on the outside of the house and unknowingly trapped the babies inside, who are now frantic and hungry.
Outside of these rare scenarios, the “baby squirrel” in the house is more likely to be a flying squirrel. A flying squirrel has a flat tail and very large dark eyes, and looks more like a chipmunk than a gray squirrel.
We can usually sort out what really happened with a few basic questions about noise patterns, physical characteristics, and droppings.
Winter Evictions Are Inhumane
Flying squirrels spend the winter together, with a dozen or more piled into a single cavity, because they are small and lose body heat quickly, and the shared warmth of the group is how they get through the cold nights.
Flying squirrels do not hibernate. They stay active all winter, but on the coldest nights they stay in the den instead of going out to forage, and live on the food they have stored. Unlike gray squirrels, who bury their food all over the yard and dig it up as needed, flying squirrels often keep a large share of their food inside the den itself.
This is why a midwinter eviction for flying squirrels is inhumane. The evicted squirrel loses its den, the warmth of the colony, and its food supply on the same night, and the food is now sealed inside a house it cannot get back into. A squirrel box nearby may help it stay warm, but it will still go hungry on cold nights if it can’t find a way to replace those food stores.
With flying squirrels, the timing of the work matters greatly. Our guide on whether squirrels should be trapped, evicted, or excluded covers this in detail.
Will They Just Leave in the Summer?
There is a stretch of the year when a colony may temporarily leave an attic on its own. After the spring litter is grown and before the summer litter arrives, the colony may move out of the excessively hot attic to cooler tree cavities. However, not every attic gets hot enough to push them out, and they will very likely be back as soon as the temperatures begin dropping again.
Though there are other times of year when flying squirrels can be removed from a home, this is usually the best time of year to complete the exclusion project. However, since the timing of litters can shift, and because it is not guaranteed they are gone even if the noise has subsided, no holes should ever be sealed without first being tested.
Professionals will test the openings as they seal a home. They may gently stuff newspaper into holes to see if it’s disturbed, or set up cameras near the most active areas to watch for movement.
Though this slows the project down a little, it is vital, since sealing up an attic while the colony is still inside creates much larger problems. A flying squirrel that is trapped will attempt to frantically chew new holes to get out. They will sometimes fall down into wall cavities, or come into the living space through whatever gaps the drywall already has. Some end up dead and rotting inside the walls.
How Do I Get Them Out and Keep Them Out?
Flying squirrels can get through very small openings, gaps about the size of a quarter, and most homes have many of them. In addition to the gaps that already exist and are large enough for their entry, a flying squirrel can chew new gaps and expand smaller ones. This means that if you want the home to stay protected, the areas that are vulnerable but not yet open have to be reinforced as well, not just the holes that exist today.
Flying squirrels are also capable climbers that will travel up through wall cavities, so the entry points are not always at the roofline, and they can be found entering a home through the foundation and lower siding as well. An inspection that only looks at the roof can miss them entirely.
Trapping is rarely the best solution for a flying squirrel problem. For starters, relocation is far less humane than eviction even when it is done as carefully as possible. Most flying squirrels will not survive a relocation. Second, when you trap you do not know if the sealing was sufficient. This is because if you evict but missed something, they will break back in within a few days, and you’ll immediately know that the job isn’t finished yet. When you relocate the squirrels you lose that immediate feedback, and have no idea whether your home is still vulnerable to the next colony.
Furthermore, once a colony has adopted an attic, it is an established den site, and other flying squirrels in the neighborhood will find the same openings. It is virtually guaranteed that at some point in the future new squirrels will move in. It’s imperative to know the project was truly successful while still inside the guarantee window.
A flying squirrel project is only finished when every gap on the house has been sealed, every vulnerable area has been bolstered, and the colony has exited with no way back in. When the work is performed by a competent and trustworthy company, it should always come with a long-term guarantee.
If you are in Middle Tennessee, and you suspect you may have flying squirrels, call us at (615) 422-5923 and we will be happy to talk it over and give you a quote.
This article is general wildlife information for Middle Tennessee homeowners. Species, colony size, and timing vary by structure. For a specific attic, have it inspected.
