By this time you should be finding dead ants instead of live ones.
My Mum has her house sprayed yearly for ants and by this time she has dead ants everywhere. It sounds like the guy who sprayed the house didn't do it properley.

My Mum cuts down lids and puts antrid in them and them just leaves them. You have to not touch the lids except to add a bit of the liquid as if you move them they move. It takes about a week but it really works for her. Inside she will often have 3 bait sites on the go.

If you know where they are coming in, blutack works to plug the hole.