There are two main types of squirrel nests: a drey and a cavity nest. Dreys are the balls of dead leaves, twigs and grass that you often see high up in the bare branches of trees during the winter. Cavity nests are squirrel nests built inside a hollowed-out tree. The tree provides the squirrel with safety and comfort, and sometimes even a food source. Squirrels also have “vacation homes” which are a third type of nest that is used to rest and store food along their scavenging route. Squirrels will often build their nests inside your attic, as your attic provides a very safe, secure place where squirrels can rest and raise their babies in peace, without fear of harsh weather or predators. Squirrel nests inside your attic may be a main nest or a vacation home, but either way, they can cause a lot of damage. 

It might sound nice to let a family of squirrels stay in your attic, but in actuality, squirrels are dangerous wild animals, and nesting in your attic can pose a danger to both you and them. Squirrels will chew on wires and wood, rip up your attic insulation, and soil it with their urine and feces. Squirrels might also bring in outside nesting materials, which can react with chewed wires and torn insulation and cause a fire. Squirrels also carry parasites like mites, fleas and ticks, and can spread illnesses like leptospirosis, tularemia and salmonella.