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Squirrels

Native & non-native species in the Pacific Northwest

Updated Mar 29, 2023

Make a Positive Identification

The most common tree squirrels in urban areas include the native Western gray squirrel, the Douglas squirrel, and two non-native species. In some semi-rural locations, native ground squirrels are active.

Telling squirrel species apart is difficult. Several native squirrel species carry legal protections. They can’t be killed or trapped and released without a special permit. The laws vary by state.

If squirrels are nesting in your attic, contact a wildlife control operator to make sure you comply with your state’s wildlife laws:

Oregon Wildlife Control Operators (Oregon Department of Fish and Wildlife)
Washington Wildlife Control Operators (Washington Department of Fish and Wildlife)

They have the expertise, licenses, and tools to get the job done right and minimize risks to your home and family.

See How to Hire a Wildlife Control Operator to learn what to look for in a wildlife control professional.

Common Squirrels

Species: Western Gray Squirrel

Fish Demon at English Wikipedia, CC BY 3.0, via Wikimedia Commons

Western gray squirrels (Sciurus griseus) are native to the Pacific Northwest. Their fur is white on their belly and silver-gray on the rest of their body. Adults of this species range in size from 19–24 inches long. When disturbed, they make a hoarse barking sound. Populations of the Western gray squirrel are in decline in Oregon. The non-native squirrel species are displacing them.

Species: Eastern Gray Squirrel

Rebekah D. Wallace, University of Georgia, Bugwood.org

Eastern gray squirrels (Sciurus carolinensis) are non-native to the Pacific Northwest. They are displacing and out-competing native squirrels. They can host a virus deadly to the native gray squirrels. They look similar to the Western gray squirrel, but are smaller and have more brown and red hairs in their coats. Adults of this species range from 15–20 inches long.

Species: Eastern Fox Squirrel

Joseph Berger, Bugwood.org

Eastern fox squirrel (Sciurus niger) is also non-native to the Pacific Northwest. These are displacing native squirrels. Their fur is reddish-brown. Adults of this species range from 18–24 inches long. The Eastern fox squirrel is the most common squirrel in the Portland metro area of Oregon. They breed nearly year-round in the moderate climate of Western Oregon.

OREGON NATIVE SQUIRRELS WITH LEGAL PROTECTION (NON-GAME)

Species: Douglas Squirrel

VJAnderson, CC BY-SA 4.0, via Wikimedia Commons

Douglas squirrels (Tamiasciurus douglasii) live mostly in conifer forests. They are found in some neighborhoods. Populations are declining. They rarely require control efforts.

Helpful

The Douglas squirrel is classified as a Non-game Protected Wildlife species. They can’t be killed or trapped and released without a special permit from the Oregon Department of Fish and Game (OAR 635–044–0430).

Species: American Red Squirrel

Cephas, CC BY-SA 3.0, via Wikimedia Commons

American red squirrels (Tamiasciurus hudsonicus) are abundant in northeastern Oregon at high elevations. They rarely require control efforts.

Helpful

The American red squirrel is classified as a Non-game Protected Wildlife species. They can’t be killed or trapped and released without a special permit from the Oregon Department of Fish and Game (OAR 635–044–0430).

Species: Northern Flying Squirrel

Angie spuc at the English Wikipedia, CC BY-SA 3.0, via Wikimedia Commons

Northern flying squirrels (Glaucomys sabrinus) live in forested areas and are nocturnal. They rarely require control efforts.

Helpful

The Northern flying squirrel is classified as a Non-game Protected Wildlife species. They can’t be killed or trapped and released without a special permit from the Oregon Department of Fish and Game (OAR 635–044–0430).

LOOK-ALIKES: GROUND SQUIRRELS AND CHIPMUNKS

Species: Ground Squirrel

California ground squirrel with spotted fur

Howcheng, CC BY-SA 3.0, via Wikimedia Commons

Ground squirrel species (Spermophilus spp.) range widely in appearance. They all tend to have shorter, less bushy tails than the tree squirrels described above. Most ground squirrels build and use burrows. One species, the California ground squirrel (shown in photo), is known for climbing fence posts, trees, and other structures. They build extensive burrow systems. Ground squirrels can climb small trees but rarely do.

Different risks or methods

Ground squirrels are a pest of concern in Central and Eastern Oregon. They are also present in the Willamette Valley and adjacent locations. They cause damage to crop fields and earthen structures such as ditches and dams. Their burrows sometimes undermine structural supports.

For management information, see OSU’s Controlling Ground Squirrel Damage to Forages and Field Crops, Ditches, and Dams (PDF).

Species: Chipmunk

ALAN SCHMIERER, CC0, via Wikimedia Commons

Chipmunks (Tamias spp.) are generally smaller and have prominent stripes. They rarely require control efforts.

Helpful

If chipmunks get in your attic or structure, follow the instructions described in this article. To learn more about chipmunks, see Squirrels, Chipmunks and Marmots (Oregon Department of Fish & Wildlife).

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Squirrels Benefits

Squirrels help forests regenerate by spreading seeds that grow new trees.
They are a food source for hawks, owls, coyotes, bobcats, and snakes.
Squirrels are fun to watch. They are superb acrobats. They have excellent problem-solving skills, especially when trying to get food.

Squirrels Risks

Squirrels may bite when fed. They carry diseases and parasites that infect people.
They build dens inside human structures such as attics when they are able to gain entry. They can chew their way into wooden buildings.
Squirrels chew hard objects in order to manage their ever-growing incisors. They sometimes damage electrical wiring (and cause fires), yard furnishings, and even metal doorsteps.
Squirrels remove fruit and nut crops from trees. They can quickly strip a tree of its crop.
They cause damage to crops, flowers, and lawns by digging and chewing.
Squirrels can damage trees by stripping away bark to feed on cambium when other natural food crops fail.

Risk Card

Does it cause harm?

Adults & Children

Low

Property

Some

Pets

Low

Annoyance

Some

Environment

Helpful

Action Depends on Context

Take Action?

Take action for squirrels nesting in attics and structures

Do I need to take action?

Remove squirrels that enter your buildings. Keep them from regaining entry.
If you grow fruit or nut crops and squirrels are a problem, take preventive action to protect your crop.

What if I do nothing?

Squirrels nesting in attics can lead to structural damage and a smelly mess with feces and urine.
Squirrels cause damage to fruit trees and gardens, but you can learn to live with them.

NEED HELP?

Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.

Solutions for Squirrels

Don’t feed squirrels. They become more aggressive when fed. Remove bird feeders if squirrels are eating the bird food, or modify feeders to exclude them.
Don’t let squirrels gain access to buildings. Repair any gaps that allow squirrels entry into structures.
Use barriers such as wire cages to exclude squirrels from garden beds and fruit crops.
Repellents may be temporarily effective.

Method	Does it work?	Is it safe?	Recommendation
A Block Access to Buildings	Very effective	Low risk	Recommended
B Protect Plants with Cages	Effective	Low risk	Recommended
C Rodent Repellents	Somewhat effective	Low risk	Use if Necessary
D Trapping & Relocating	Does not work	High risk	Illegal
E Rodenticides are NOT ALLOWED for Squirrel Control
F Prevent Squirrel Problems

Block Access to Buildings

Non-Chemical Method

Liz Kasameyer, Johns Hopkins School of Public Health, Bugwood.org

Block Access to Buildings

Recommended

Seal squirrel entry points with wire mesh. The photo shows wire mesh covering a vent on a structure. The wire excludes animals such as squirrels, birds, and rats.

Does it work?	Very effective Blocking access to your home and structures is required to keep animals from coming back. It is also a key method to prevent animals from damaging structures.
How much effort?	High effort Use good carpentry practices and sealing techniques to close off entry points.
What's the risk?	Low risk
Possible risk of exposure or harm from chemicals	NONE

Squirrels accessing structure trough damaged facia

tillsonburg, iStock

Examine your structures for potential squirrel entry points such as the one shown in the photo.

How to Exclude Squirrels from Structures

Seal squirrel entry points with wire mesh.
Repair any gaps that allow squirrel entry to structures.
Close openings with ¼ to ½-inch welded-wire mesh. Cover dryer vents, chimneys, and drain/waste/vent pipes with a welded wire screen or cap firmly affixed to the feature.
Trim trees to a minimum of 10 feet away from buildings to prevent squirrels from jumping onto roofs.
Remove trellises and vines that provide squirrels a way to climb structures.

Protect Plants with Cages

Non-Chemical Method

pcturner71, iStock

Protect Plants with Cages

Recommended

Use wire cages to exclude squirrels from vegetables, fruits, and flowers to keep the animals from digging up plants.

Does it work?	Effective Wire cages must be constructed without gaps to exclude squirrels from entering an area.
How much effort?	High effort Use good building practices to close off entry points.
What's the risk?	Low risk
Possible risk of exposure or harm from chemicals	NONE

Rodent Repellents

Chemical Method: Use with caution

Weston Miller, Oregon State University

Rodent Repellents

Use if Necessary

Rodent repellents have a strong taste or smell that repels rodents and wildlife without causing them harm.
Repellent active ingredients include capsaicin (pepper extract), castor oil, peppermint oil, clove oil, and other essential oils. Other repellents mimic predator scents.

Does it work?	Somewhat effective Repellents may provide temporary control of squirrels. Most repellent products have not been subjected to objective scientific tests of effectiveness or length of effect.
How much effort?	Moderate effort You must reapply repellents every two weeks or after heavy rains.
What's the risk?	Low risk Rodent repellents are NOT toxic baits (rodenticides) designed to kill rodents.
Possible risk of exposure or harm from chemicals	Using animal repellents includes some amount of risk. The lowest risk comes with using alternative methods. You may be exposed to an animal repellent if you: Get it on your skin Breathe it in Eat or smoke afterward without washing hands Bring it inside on your shoes or clothes Follow directions closely to reduce risk.

More Information About Rodent Repellents

If using repellents, remember to rotate among different products: Animals quickly habituate, or learn to ignore, any signal that is never associated with a negative consequence.
Most repellent products must be applied to the surface of plants: Products will lose effectiveness or be washed off completely in repeated moisture or precipitation events and will likewise be degraded by the sun’s UV rays over time. Reapplication and rotation of products is vital.
Follow the label instructions about reapplication rates and timing.

Trapping & Relocating

Not Recommended

"Squirrel Removal" by SheltieBoy is licensed under CC BY 2.0.

Trapping & Relocating

Illegal

Trapping and relocating squirrels is legal in very limited circumstances and only in cooperation with your state’s wildlife control agency.

Does it work?	Does not work Other squirrels will move in to replace the ones you have removed.
How much effort?	High effort Trapping and relocating squirrels is best left to professionals who have permits and comply with state laws.
What's the risk?	High risk Relocating squirrels to new areas can spread disease to an otherwise healthy population. Most (more than 50%) translocated animals die a lingering death. Increased risk of predation, starvation, roadkill, and aggression from squirrels already on site contribute to mortality.
Possible risk of exposure or harm from chemicals	NONE

Details about Trapping and Relocating Squirrels

Trapping NATIVE squirrels requires a permit. The permit allows them to be captured and released on the same property. You need to coordinate with your state’s wildlife management agency.
Live trapped NON-NATIVE squirrels may be released on the same property where they are trapped. Otherwise they must be humanely euthanized.
Hunting native squirrels requires a license.
We recommend you hire a wildlife control operator with a permit to handle squirrels.

If you want to trap and relocate squirrels, contact a wildlife control operator to make sure you comply with your state’s wildlife laws:

Oregon Wildlife Control Operators (Oregon Department of Fish and Wildlife)
Washington Wildlife Control Operators (Washington Department of Fish and Wildlife)

They have the expertise, licenses, and tools to get the job done right and minimize risks to your home and family.

See How to Hire a Wildlife Control Operator to learn what to look for in a wildlife control professional.

Rodenticides are NOT ALLOWED for Squirrel Control

Chemical Method: Use with Caution

cmannphoto, IStock

Rodenticides are extremely toxic to humans, pets, and wildlife. Baits are made to attract animals with tasty smells and flavors. The hawk in the photo could be poisoned if it ate an animal that consumed rodenticide.

Why Is It Important to Read Rodenticide Labels?

They have detailed information on how to use the product correctly and legally.
They contain information about specific rodent species, their habits, and control methods.
They provide information on potential hazards of the product, with instructions you should follow for poisonings and spills.

The Label is the Law

ALWAYS read the label before using rodenticide products. The label is a legal document that provides information on how to safely use the rodenticide. This helps avoid harm to human health and the environment. Using a rodenticide in off-label ways is illegal. It can result in legal enforcement actions.

READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.

Rodenticides (toxic baits) available at stores are NOT ALLOWED for control of squirrels and other wildlife. It is unlawful to use rodenticides in a manner inconsistent with their labeling (instructions).

Labels are different for every product and they often change over time.
Use a magnifying glass.
Pay attention to CAUTION, WARNING, and DANGER statements.
Pay attention to the PRECAUTIONARY STATEMENTS.
The law states you must read and follow rodenticide instructions.

Storage & Disposal

Store out of the reach of children and pets.
Follow the label instructions for disposal of rodenticide products.

Call 1-800-CLEANUP (1-800-253-2687) to find out where to dispose of pesticides.

For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call 503-234-3000, email or visit Metro’s website

More about:

About Using Pesticides on School Grounds in Oregon

If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management (Oregon Department of Agriculture).