What exactly is an exterminator anyway? An exterminator is a person who specializes in eliminating pests and insects inside or out of a house or business. Exterminators can also use natural remedies and chemicals to eliminate pest infestations as well. If you have insect problems in your home, office, or building, it is always a good idea to hire an exterminator to get rid of the problem. One of the most common pests that an exterminator will deal with are mice and rats. Rats and mice can be a real nuisance for a lot of people especially during the cold winter months when they can be a huge headache to have in the house.