The time of day you are hearing the noises may indicate what type of animal has made a home in your attic. Fireplace chimneys and soffit areas above garages and attached structures can also be living quarters for animals.
Noises heard during the late evening hours between 10 p.m. and 4 a.m. could indicate a raccoon. Noises heard in the morning or daytime would be more indicative of squirrels. The solution is to make the animal's living quarters as uncomfortable as possible. This can be accomplished by placing a few household items (i.e. trouble light, radio set to a talk station, ammonia soaked rags) in the area where the animal lives. The combination of light, noise, and odor in the animal's "home" will typically help to drive it away.
You must also locate the opening(s) that allowed the animal's entry. These openings should be temporarily covered with plastic to see if the animals have left. Once you establish that the animals are gone, the openings should be permanently repaired.
For more information, you can contact Animal Control at 847-982-5970.