Squirrel Biology and Habits
Fox and Gray squirrels are active from dawn to dusk, with most feeding occurring in the early morning, and then again in the mid-afternoon. These tree squirrels usually feed on fruits, nuts, and other vegetation.
Squirrels may breed twice a year (usually around January and June) and have a 42 - 45 day gestation. They usually have 2 - 3 young that are weaned at 10 - 12 weeks and can live up to 4 years old in the wild.
These rodents nest in tree cavities, leaf nests, and attics or crawlspaces. Common entries to the home are roof vents, louvre vents, soffit vents, construction gaps, and rotten fascia boards.
While most trespassing squirrels are merely a nuisance, they can pose a real threat to humans. It is estimated that 25 - 50% of all fires of unknown origin are caused by rodents gnawing electrical wires. Squirrels are known carriers of diseases like encephalitis and typhus, although they are generally not carriers of rabies.
Damage concerns include squirrels chewing bark off trees and shrubs, squirrels raiding crops and bird feeders, and squirrels shorting out transformers while traveling power-lines. In the fall and winter months squirrels enter dwellings for shelter, and in the spring they enter to raise young.
Squirrel trapping techniques usually include cage traps for live-trap and squirrel removal, and are usually baited with nuts and/or peanut butter. Live squirrel traps are set in the line of travel outside the den entrance (squirrel traps are not set inside because there is poor light and the den is a shelter, not a feeding site).
Squirrels inside the home almost always come in through the fireplace or furnace chimneys and should only be removed by trained personnel with the proper safety equipment (gloves, traps, control poles, etc.).
Toxicants are illegal and are not used in squirrel control (squirrels may die in wall voids and cause odor problems). There may also be secondary poisoning hazards to pets (e.g. dogs that eat sick squirrels) and children may be bitten trying to assist sick animals.
Trimming trees back 8-12 feet from the structure will help to prevent roof access for squirrels. Critter Control uses sheet metal, hardware-cloth, aluminum or wood to seal and close up entry holes to prevent future squirrel access. For chimney squirrel exclusions, Critter Control technicians install only NFPA 211 and BOCA approved chimney screens and rain-caps to prevent squirrel entry. Chimney caps are available in black galvanized or stainless steel models and come in a wide range of sizes.