Squirrels are rodents that belong to the rodent family. They can grow to be up to 18 inches long and weigh around a pound. Squirrels do not hibernate during the winter and remain active all year. They eat acorns and nuts that were buried in the autumn during the cold months, but they don't remember where they hid their food, contrary to popular perception. The food they find using their acute sense of smell was most likely hidden by another squirrel. The squirrel can find enough food to survive even if it is covered in snow.
Because wildlife has adapted to living in close proximity to us, they don't mind sharing our homes. They frequently gain access to a home by chewing through roofing shingles or by discovering a small hole along the roofline and chewing it open until it is large enough to break entry. Vents are another common entry point for them into your home. Squirrels, for example, can wreak a lot of damage if they chew on electrical lines, and given the nesting materials they've brought into your home, they could even start a fire.