Female squirrels typically have two litters that contain an average of two to four young each year. However, depending on a variety of factors including food supply, weather conditions, and habitat, squirrels are capable of carrying up to eight young in one brood. Litters are usually born in late winter and then again during midsummer. Pregnancy lasts up to two months, and the young are born hairless and weigh around 13 to 18 grams, or 0.5 to 0.65 ounces. Squirrels are completely weaned from the mother after approximately two months, and adulthood is reached in nine months.
Due to predation and hunting, squirrels' lifespans can vary drastically. The pests experience high mortality rates in their first year of life but are capable of living up to 15 years in the wild. The average squirrel lifespan is between five and six years. Since the pests are prolific breeders, homeowners dealing with squirrel infestations see populations rise dramatically. Once squirrels establish themselves as a major issue, individuals should contact pest control specialists.