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). 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. Once the squirrels have been eliminated from the building, be sure to repair any damage they caused. To prevent further damage, trim all trees which have limbs within eight feet of the building.
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. 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, a .17 caliber rifle, or .22 caliber rifle are 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 (FIGURE 3) directly over the open entrance. As the animal passes through the opening, it will be killed instantly. Another method of lethally 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 (Figure 4). Another option is similar to the conibear trap but is within a metal tube helping to limit access of non-target animals (Figure 5). The trap is versatile to a variety of positions including placement on t tree branch or trunk. Just insure it is secured to the spot it is placed otherwise its effectiveness decreases. It can be placed with or without bait.
Squirrels can also be captured with live cage traps (Figure 6). 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 are present.
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.