Squirrels are very agile Rodents with big fluffy tails, can climb trees and jump incredibly well. They nest in trees. Squirrels can be found in the woods and the city. The squirrels in the cities have become almost dependent on humans. They do not have much in the way of of a Squirrels Natural Environment in the city so its attics and under eaves where they end up.
Eastern Gray Squirrels are Rodents (like Mice and Rats) and can reach in size up to 17" to 20". They have grey fur, their bellies are a more pale grey. The tail has silver hairs at the end and is very bushy.
Squirrels have no aggressive nature, but they will bite to defend themselves. Leave them alone and they will leave you alone.
Signs of having Squirrels are noises. They are usually active during the day and make a lot of noise as they run around. In the attic, you might see leaves, twigs and balled up insulation, this indicates a possible nest. You may find a cache of nuts. Another sign is squirrel droppings which are usually black smooth and oval in shape.
Squirrels will enter your home from the upper levels into your attic or walls through a hole either made by them or already there. Attics make the perfect home for Squirrels; its warm, plenty of nesting material, usually tree limbs or power lines close and they feel secure there.
Inspect all places where Squirrels enter, this will require ladders. Trying to poison them may have a lot of unsatisfactory consequences. Sealing off the openings is essential for long term control. Also you don't want them blocked inside with no way out. It is best to use a Squirrel Control Expert.