Pest control companies typically address chimneys by sealing off any openings or cracks that can allow pests to enter the chimney or building. They may also use traps or bait to catch and remove any pests that are already inside. Wildlife control companies address chimneys by identifying and sealing off any openings or cracks that may be allowing animals to enter the chimney, and also remove any animals that may already be inside. They also use exclusion devices like chimney caps to prevent wild animals from entering again.