Factsheet: Least-toxic Control of Squirrels
Pest type: Animals
Squirrels are members of the rodent family. The most frequently dealt with nuisance squirrel is the Eastern Gray Squirrel. They measure around 16-18 inches from nose to tail and weigh approximately one pound. Gray squirrels are active year-round and arboreal, meaning that they live primarily in trees. They feed on a great variety of foods, such as nuts, seeds, fungi, fruits, and of course the seed in your birdfeeder. They store nuts and acorns in holes in the ground. Gray squirrels breed throughout the year, but there are two distinct peaks, in the winter and summer. After about six weeks, two to four young are born, and raised in a nest for about three months. They prefer cavities in trees (or homes), and when cavities aren’t available, they will build a nest out of leaves and twigs high in a tree.
Squirrels have easily adapted to humans. They frequently use buildings as nesting areas. Squirrels love to break into a house and stay in an attic or soffit. They often find a small opening and will chew a wider hole to gain access to the building. They bring nesting material into the home, and make quite a bit of noise scurrying around and caching nuts. They often fall down the chimney flue and make a lot of noise or enter the fireplace. Sometimes they fall down a wall from the attic and get stuck. They often chew their way into commercial buildings or apartments. They often enter the attic through the gable vent. Squirrels can cause a fire hazard in homes by bringing in nesting material, and by chewing on power lines. Squirrels can leave behind a lot of droppings and urine in the attic. The droppings not only smell bad, but they pose a biohazard, and the smell attracts new squirrels. If squirrels are outside, they may not need to be controlled, however they may become a nuisance quickly indoors.
Trim tree branches back at least 10 feet from the building.
Encircle isolated trees and power poles with a two-foot wide collar of metal six feet off the ground to prevent squirrels from climbing them. On trees, attach metal using encircling wire held together with springs to allow for tree growth.
To prevent squirrels from traveling on wires, attach two-foot sections of lightweight 2 to 3 inch diameter plastic pipe. Slit the pipe lengthwise and put it over the wire. It will rotate on the wire, causing the traveling squirrel to fall.
For preventing squirrels from birdfeeders, place the bird feeders atop of metal poles and a squirrel guard baffle underneath. If you must hang the feeder on a tree, place the feeder as far out on the branch as possible and a use a wire instead of a chain to hang it, as the wire is more slick, and baffle the feeder, or use a narrow tube feeder that squirrels won’t be able to reach from the tree trunk. Spray Teflon® on poles as a good temporary measure. Install porcupine wire around the pole of a feeder, taking care not to place it where squirrels will fall. They are unable to find firm footing in the spines and can’t climb the pole. Construct a closed cage with chicken wire (or any similar mesh wire with two-inch holes) around the feeder. Mix cayenne pepper with Vaseline and apply to the feeder pole as a repellent.
To exclude squirrels from gardens, Cage entire plants that squirrels are finding tasty. To prevent squirrels from digging in flower pots or small gardens, use hardware cloth, cut to fit around the stem of the plant and extended to the edges of the pot or garden just below the soil. Place small rocks near the edge of the pot or garden to hold it in place. Mix seeds with black pepper before planting, at a ratio of one teaspoon per pound of seed, as a squirrel deterrent.
It cannot be stressed enough how important detection, monitoring, and record keeping are to effective squirrel control. A few minutes spent monitoring and recording is extremely helpful for immediate control, and also helps to save time and resources in long-term control. The information you gather will be helpful to you and any adviser who helps you.
To remove a squirrel from a roof or attic, you must determine where they enter. Baited cage traps may be used to capture the animals coming and going from their access holes. Peanut butter, shelled pecans or walnuts are good baits. Live trapping should be aimed at minimizing stress, as squirrels can die of shock when trapped. They should be incorporated into a wooden nest box or be completely covered so that the inside is dark and protected from weather. Traps should be checked two or three times a day, especially at dusk, so that animals aren’t left overnight.
Biological controls should not be considered for control of tree squirrels.
The organic compound that has proven to best repel squirrels is cayenne pepper. The capsaicin in this substance is an irritant that repels squirrels without harming them.
Look at your product labels and try to avoid products containing those chemicals listed below:
(A = acute health effects, C = chronic health effects, SW = surface water contaminant, GW = ground water contaminant, W = wildlife poison, B = bee poison, LT = long-range transport)