Squirrels

Overview:

Squirrels are members of the rodent family.
Gray and Red squirrels are the most common in Minnesota, with the Gray being more numerous. The Fox and the Flying squirrel can sometimes be a problem. This information will deal mostly with the Gray Squirrel.
Squirrels prefer forested or treed areas: Gray and Fox inhabit both hardwood and coniferous areas, whereas the Red squirrel prefers coniferous but will also occur in mixed forested areas.
Squirrels (other than Flying) are diurnal, meaning that they are active during the day, however if trapped within a wall void they will make noise until they die or escape.

Facts:

Squirrels are the most active in late winter, when the mating season begins. The males will chase a females, as well as, chase off other suitors. This ritual of chasing, occurs through the trees at top speed. While they perform some of the most breathtaking acrobatics imaginable.
A female squirrel will choose the strongest male during mating season, but is unlikely to breed with that male again. This is natures way of reducing inbreeding, and to preserve the species.
In the summer squirrels are most active two to three hours after sunrise, then they'll rest in the afternoon. Resuming activity again two hours before sunset. The squirrel will retire to its nest well before dark, and will rarely leave the nest in the dark. In the winter, the squirrel will complete its activities between dawn and mid- day, and will remain in or around the nest until the next day.
An adult squirrel normally lives alone. But will, in severe cold, share its nest with other squirrels to conserve body heat. Once the temperature rises, the guests will be on their way.
Squirrels eyes are located high, and on each side of their head. This allows them a wide field of vision, without turning their head.
The gray squirrel requires some salt in its diet, and may find this salt in the soil along roads where snow and ice may have been.
Squirrels chew on tree branches to sharpen and clean their teeth. That's why you may see many small branches on the ground around large trees. They will also chew on power lines for the same reason, this has caused many major power outages throughout the country.
Squirrels communicate through a series of chirps. The frequency, and the duration of the notes communicate everything from laughter to alarm. These sounds when used in conjunction with tail gestures, form the basis for squirrel communication.
A squirrel will break the shell of a nut with its teeth, then clean the nut by licking it or rubbing on its face before it is buried. This action applies a scent to the nut which helps the squirrel find it later, even under a foot of snow.
A squirrels teeth grow continuously. Their incisor's will grow six inches per year, but stay short due to the constant wear they receive.
The most common type of squirrel bite is a result of feeding a squirrel by hand. Never hold the food between your fingers, chances are very good you will be bitten. A squirrel's eyes are always looking for predators and they rarely focus on what they are eating.

Identification:

As their names fortell, Gray squirrels are gray and Red squirrels are red. However, Gray squirrels come in many shades of gray and sometimes shades of brown. They can also be pure white and pure black, but both are variations of the gray squirrel.
The common Red squirrel can have an all black coat.

Biology:

Gray Squirrels breed at about 1 year of age. Squirrels are usually born in the early spring. The average litter consists of four. This varies with climate and location. A second litter can occur in mid summer, if there is an adequate food supply. Young squirrels may breed only once in their first year. Their gestation period is about 40 - 45 days.They are born hairless, blind and their ears are closed. The young begin to explore outside around the time they are weaned, which is about 10 - 12 weeks. At weaning they are about half of their adult weight, which is about one pound for the Gray squirrel, two thirds of a pound for the Red squirrel.

Habits:

FEEDING
Squirrels prefer to eat at dusk. They will eat a great variety of foods and will adapt quickly to unusual food sources. Typically, they will feed on:

Acorns
Walnuts
Other Nuts
Berries/Fruits
Bulbs
Fungus
Bird Eggs
Small Birds
Small Mammals
Dog Food
Insects
Corn

During peak population periods, when food is scarce, squirrels may chew bark from a variety of trees. Red squirrels may eat pinecones and buds. In gardens squirrels may eat planted seeds, mature fruits, or grains such as corn.

DAMAGE
In residential areas squirrels sometime travel along power lines and will short out transformers. They gnaw on wires, enter buildings and build nests in attics. They can occasionally damage lawns by burying or searching for and digging up nuts. They can chew bark and clip twigs of many ornamental trees or shrubbery planted in yards. Many times squirrels will rob bird feeders of birdseeds and in some cases chew to enlarge the openings of birdhouses in order to enter and eat nestling songbirds.

Treatment: (Control)

There really isn’t any control measures for squirrels other than trapping, however there are some preventative measures which can help to prevent squirrels from entering structures.
Trim tree branches and limbs to about 6-8 feet away from the structure to prevent squirrels from jumping on the roof.
Inspect all roof overhangs, soffits, fascia boards etc. make sure they do not have any cracks or holes and that they are tightly attached to the framing.
All roof vents should be inspected to make sure they are properly screened, not loose and in good repair.
Keep bird feeders away from the building, perhaps using a “squirrel proof” type of feeder.

Trapping

Most squirrels can be caught from the outside, close to the entrances to their nesting area.
You can easily place the traps on the underside of overhangs, soffits etc. by putting some nails or hooks into the wood soffit or fascia boards. That way you can get the trap as close as possible to the opening.
If you trap on the inside of the attic, place the traps on some boards, if placed on the loose insulation, the trap pan may not work properly.
When placing a trap on the roof, make sure it is facing up or sideways, as squirrels do not like to crawl down into a trap.
The best bait to use: cut an apple in half, spoon out a depression, fill the depression with peanut butter, stick nuts into the peanut butter. Three things are attracting the squirrel, the moisture from the apple, and the smell of the peanut butter and the sight of the nuts. You can also use peanut butter and bread.
Do not contaminate the trap with chemical, soap, odors or the scent of other animals from previous trappings. You should wash the trap after each use, use clear water, no soap or bleach.
After trapping place paper towels or crumpled newspaper into entrance holes, if it is not moved or disturbed the next day, the hole can be sealed, as there are no more squirrels using that entrance.
After trapping we recommend you relocate it at least 10 miles away in a non-residential area.
Optionally one may use large rat snap traps or large glue boards, being mindful this isn't the most environmentally friendly approach.