How to finally get rid of ants?

We have been infested with ants this season. My husband sprays Bayer ant killer outside at the perimeter of the house and also around the windows. but, they still find their way in. We don't leave food out..only fruits. Everything else is put away or in zip lock bags. They are on the floor, the counters, and climbing up the walls. They are mostly in the kitchen; however, there a few in the bathroom and even in my son's room. we also have Terro liquid traps and that works but it seems as if when 100 die another 100 take their place. What is the best thing to do? I even had a couple of ants crawling up my arms. I am just disgusted! I told my husband we need to get someone to spray and we should also spray the flower pots. Any better advice?