MANAGING TREE SQUIRREL PROBLEMS IN KENTUCKY
Thomas G. Barnes
Kentucky has three species of tree squirrels:
eastern gray (Sciurus carolinensis), northern fox (Sciurus niger),
and flying (Glaucomys volans). Gray and fox squirrels are game species,
whereas flying squirrels are not a game species. Because flying squirrels
seldom cause problems for homeowners, they are not discussed in this publication.
Fox and gray squirrels often come into
conflict with humans when they take up residence in an attic, eaves or
walls of a house. Squirrels sometimes cause damage by gnawing and removing
bark or fruits from valuable fruit and nut producing trees, ornamental
trees and shrubbery or by feeding on corn, tomatoes, strawberries and other
seeds or mature fruits in the garden.
Tree squirrels are the number one game
animals pursued by Kentucky sportsmen, but they are protected by Kentucky
law. You must contact your local conservation officer before attempting
any control measures.
The eastern gray squirrel is the most
common tree squirrel found in Kentucky. These medium-sized rodents have
a bushy tail. They are 16 to 20 inches long and weigh 1 to 2 pounds. Gray
squirrels vary in color from gray to brownish gray with a white belly.
Completely black (melanistic) and white (albino) forms are also encountered
The northern fox squirrel is Kentucky's
largest tree squirrel. Fox squirrels measure 18 to 27 inches, including
their bushy tail, and weigh 1 3/4 to 2 1/4 pounds. Fox squirrels are typically
grizzled gray with a touch of yellow or orange upper parts and pale yellow
to bright orange underparts. The fox squirrel's tail usually has numerous
yellow-tipped hairs, while gray squirrels have white-tipped tail hairs.
Animal Biology and Facts
Both fox and gray squirrels are common
in Kentucky. The favorite haunts of gray squirrels are largely forested
habitats dominated by oak and hickory trees and city parks or suburban
yards. Fox squirrels like relatively open country with oak, hickory and
walnut trees scattered along fence rows or occurring in small groves.
Squirrels require large old trees which
produce their favorite foods: acorns, hickory nuts, walnuts and Osage orange
fruits. During the spring and summer when nuts are scarce, squirrels eat
tree buds, fruits, berries and succulent green plant material. In the fall
they are very busy collecting nuts and storing them for future use. Old
mature trees are also necessary for nesting because squirrels prefer nesting
in tree cavities, leaf-nests high in a tree or man-made den boxes.
Squirrels are active during the day.
Most activity occurs in the early morning and late afternoon to early evening.
Squirrels do not hibernate and are active year round. During late December
through January and June through July, squirrels become very active and
noisy as they prepare to mate.
Squirrels typically breed when they
are one year old. Three to four blind and naked young are born in March/April
and September after a 42- to 45-day gestation period. Newborn squirrels
weigh about one-half ounce and open their eyes after about 32 days. Young
begin exploring outside the nest when they are weaned at 10 to 12 weeks
Home range and movements of squirrels
vary widely. Most activity is concentrated within several acres although
squirrels have been reported to range from 1 to 100 acres. One study reported
squirrels traveled 50 miles during the fall in search of suitable habitat.
Squirrel populations periodically rise
and fall and are intricately linked to the quantity and quality of available
habitat. Like most small game species, squirrels have high reproductive
and death rates. Normally more than 50% of the squirrels in a population
die each year. Squirrels are a favorite food of many predators, including
hawks, owls, snakes, foxes, house cats and dogs. Squirrels are also susceptible
to a variety of parasites and diseases, including ticks, mange mites, fleas
and internal parasites. Most squirrels in the wild never reach four years
Preventing and Controlling Tree Squirrel Damage
The best long-term solution to managing
squirrel problems in the home is to exclude or "build them out" of a building
or attic. Because squirrels are rodents and have large front teeth, you
must use 1/4 or 1/2-inch hardware cloth or 26 gauge metal when excluding
squirrels from buildings. Do not use steel wool or window screening; the
squirrels can chew through it.
The best way to eliminate squirrels
that have entered a building is to find all their entrances and travel
routes. Be sure to look for eave openings, attic vents, loose flashing
around chimneys and pipes and openings around cables. Plug all entrances
except one, and set a trap at the open entrance (see section on trapping
below). Once the squirrels have been eliminated from the building, be sure
to repair any damage they caused. Then use the preventive measures outlined
To prevent further damage, trim all
trees which have limbs within eight feet of the building. Squirrels can
be discouraged from climbing trees if you put a band of two-foot-wide sheet
metal six feet away from the bottom of the tree. Remove any branches less
than six feet from the ground to prevent squirrels from jumping onto them.
If the squirrels are gaining access via telephone or electrical wires,
put a two-foot section of lightweight 2- to 3-inch diameter plastic pipe
over the wire by slitting the pipe lengthwise and placing it over the wire.
Be careful not to touch the wire. The pipe will rotate on the wire causing
squirrels to tumble.
Squirrels may temporarily vacate an
attic and give you enough time to seal entrances if you place mothballs
correctly throughout the attic. Use one pound of mothballs per 100 square
feet of attic space. Because the mothball vapors are heavier than air,
they must be suspended in baseball-size clumps close to the damaged area.
Using old pantyhose is an inexpensive, effective way to do this.
One method of controlling and preventing
squirrel damage is to reduce the population through shooting or trapping.
In rural areas squirrel populations can be reduced effectively by hunting.
You must have a valid Kentucky hunting license to shoot squirrels. If you
hunt at times other than normal Kentucky hunting seasons, you must contact
your local conservation officer before killing any squirrels. Because squirrels
are most active during the morning and evening, concentrate your hunting
activities during these periods. Many types of firearms are capable of
taking squirrels, but a shotgun loaded with #6 shot shells or a .22 caliber
rifle is most effective.
A variety of traps can be used to catch
squirrels. If you know the squirrels' entry point and you can easily reach
it without endangering yourself, place a #110 conibear trap directly over
the open entrance. As the animal passes through the opening, it will be
Squirrels can also be captured with
live cage traps (Figure 1 ). To be effective, these traps must be pre-baited
and wired open for several days before trapping. A variety of baits works
well, including peanut butter, walnuts, pecans, apple or orange slices,
corn and sunflower seeds. To prevent squirrels from returning, take trapped
squirrels at least 5 to 10 miles from the capture site before releasing
them. If squirrels are entering an attic where there is space to set a
live trap, place the trap immediately behind the opening and catch the
squirrel as it enters the building. Do not remove squirrels when young
One box-type of trap has been effective
in California. This trap, shown in Figure 2a, Figure 2b and Figure 2c is
placed in adjacent trees. A final method of trapping gray squirrels is
to use rat-snap traps nailed to a tree or house 15 to 20 feet above ground.
The traps should be baited with peanut butter or sweet corn.
No poisons or fumigants are registered
for controlling tree squirrels in Kentucky. One method of keeping squirrels
from browsing on trees and gnawing on wood is to use a chemical repellent.
Repellents do not stop gnawing damage but do reduce the severity of damage.
The best repellent is one containing Thiram. Always follow label instructions
for using any chemical substance.
Old reports found in the literature
suggest repellents containing polybutenes can be used to repel squirrels.
The substance burns the squirrels' feet. The following substances can be
sprayed on wood to repel squirrels: ( 1 ) One pound of copper napthenate
mixed in 2 1/2 quarts of mineral spirits. (2 ) Three pounds asphalt emulsion
and 2 pounds copper carbonate mixed in 2 quarts of water. (3) One teaspoon
of Lysol® or 3 ounces epsom salts mixed in 1 gallon of water. Several
of these solutions may discolor wood; treat a small area hidden from view
first to determine the amount of discoloration.
Be patient and persistent. Wildlife
damage problems are rarely solved quickly. Once the squirrel problem has
been eliminated, be sure to repair any damage to remove the attractive
feature and prevent further damage.
About the Author
Tom Barnes has worked at the University
of Kentucky's Department of Forestry for two years as an Extension specialist
in wildlife. After working on his master's degree at South Dakota State
University, he worked in the state Game, Fish and Wildlife department and
at the U.S. Fish and Wildlife Service. He also gained experience in the
field while working at U.S.D.A. Animal Damage Control. He has published
information on mice, rabbit and vole damage to trees. His Ph.D. from Texas
A&M is in wildlife management.