How to Deter Squirrels in Residential Settings

Stephanie L. Richards, PhD, Medical Entomologist

We have all probably heard it…the scratching sound of tiny claws scampering across the roof. Then one day, you notice a hole on the exterior of the house in the soffit under the roof. When you investigate further, it looks like the hole has been chewed open. An investigation of the attic results in an animal scurrying away in the corner and you may see chewed wires and evidence of debris (e.g., nesting material, excrement) from squirrels residing there.

Or perhaps new seeds have just been planted in your garden, and when you check the plantings the next day, you find that all of the seeds have been dug up and eaten by squirrels. You once thought it was cute how squirrels dashed about your yard, eating nuts and jumping from branch to branch. You now resolve to rid your yard of squirrels before they do any more damage. Knowing what attracts them is important for learning how to help deter squirrels in residential settings.

How far do squirrels travel from home?

Squirrels (e.g., tree squirrels, ground squirrels, flying squirrels) are rodents that live four to six years in the wild. They inhabit hollow tree cavities (higher survival rate in this type of home), but they can also be found in leaf nests (lower survival rate in this type of home). The home range of most squirrels is from 1 - 8 acres, depending on the rank of the squirrel, i.e., dominant squirrels will have larger ranges than other squirrels.

What do squirrels eat and drink?

Time of year and weather influences squirrel abundance, as this is related to food and water availability. If water is available (e.g., fountain, pond), squirrels will use this source; however, other sources of water (e.g., dew, succulent plants) are suitable for squirrel survival. The type of food that squirrels eat depends on geographic location, availability of food sources, and season. Some examples of squirrel food are: nuts, berries, flower buds, flowers, mushrooms, bark, roots and seeds.

Are squirrels a public health issue?

Squirrels can be involved in the epidemiologic cycles of several pathogens (e.g., bacteria and viruses) that impact public health, i.e., diseases such as: Colorado tick fever, La Crosse encephalitis, Lyme disease, typhus, West Nile virus. Pathogens that cause these diseases require an arthropod (i.e., mosquito or tick) for transmission from squirrels to humans.

How can I help keep squirrels away?

A thorough inspection of the exterior of houses/outbuildings can be carried out by pest control professionals. If any damage (i.e., holes in soffit) is observed, this should be fixed immediately and properly. Potential entry points should be properly sealed to help keep squirrels out. If squirrels are suspected in the attic or other spaces, electrical wires should be inspected by a professional electrician for damage as chewed coverings on wires can be a fire hazard.

Tree branches should be properly trimmed by a professional so none are touching the house (within 6 - 8 feet) as squirrels may see this as a roadway to the house.

Garden beds can be covered with a layer of fine wire mesh to help prevent squirrels from eating planted seeds. Once crops have grown and are producing fruit or vegetables, wire mesh fences may be crafted to help keep squirrels from eating the tasty produce.

Visual deterrents that simulate predators, such as plastic owls, cats, hawks, and/or snakes can be attached to trees, fences, or homes with some success against squirrels, at least for a few days. Squirrels tend to be good at determining the threat level of inanimate objects and become comfortable with their ever-presence very quickly. Mechanical moving objects, such as a plastic owl in simulated flight, can be more effective at scaring/deterring squirrels than stationary objects, but they won’t fool squirrels for long either.

Electronic devices that produce ultrasonic sounds to annoy animals have also been used against squirrels in small areas, such as attics. Recordings of frightening sounds (e.g., firecrackers, human voices) have been employed to repel squirrels. While these devices may temporarily be successful at warding off squirrels, the effects are generally brief as the rodents become accustomed to the sounds.

Are there any predators that will eat squirrels in residential settings?

Predators of squirrels depend on geographic range but can include: cats, dogs, rat snakes, hawks, owls, foxes, etc. In some areas, people consider squirrels a delicacy…squirrel casserole, anyone? Of course, in some municipalities, squirrels are protected and can only be taken in accordance with state or local game laws.

Sound, odor, and visual deterrents used in combination with exclusionary methods (e.g. sealing up entry points) provide the greatest success for deterring squirrels from residential settings. Pest control professionals can be consulted for advice on these options. It is possible for squirrels and people to exist together…as long as the squirrels are encouraged to stay outside.