There are many different kinds of ants in the United States. Some require specialty treatments. Before you decide to treat for ants yourself, find out what kind they are.
Some ants require a specialty treatment. Among them are the pharaoh ant. This ant requires a special kind of treatment. If you spray for these ants you'll just scatter them throughout your home. So no spraying for pharaoh ants, please.
The pharaoh ant is the little tiny ant that people sometimes call sugar ant or piss ant. Don't confuse these with other little tiny ants.
The Pharaoh ant is only about 1/15 to 1/12 inch long and very light colored. A real light yellowish to reddish brown. The way to distinguish them from other little tiny ants is by the presence of three segments on the antennal club. You'll have to have a microscope to see these segments.
They will invade your kitchen and bathroom and other areas throughout your home. If you want to treat for these ants yourself go to your local hardware store or home improvement center and buy a product called Terro. Read the label and apply accordingly in the areas you are seeing the pharaoh ant. Come back and inspect in a short while and you'll probably see them feeding on this bait.
If you have to call your local pest control company they are probably going to do the same thing and use the same thing anyway or something simular. You save yourself some time and money. This product also works on other small ants also.
If you are unsure of what kind of ants you have, call a professional you can trust for a free inspection. After all you don't have to buy their service.
Update: There are now certain chemicals that can be used to spray for Pharaoh ants. However these chemicals are not the normal insecticide repellent chemicals. One is called Phantum for indoor use and the other is called Termidor for outdoor use. Termidor is probably the best termiticide on the market for termites but is also labeled for ants also. However, both of these chemicals are only available to pest control professionals at this time.