Dissolve 1 tsp. boric acid and 6 tblsp. sugar in 1 cup water. Soak some cotton balls in solution. Make bait dispensers from margarine containers by punching holes in container lids. Put cotton balls inside margarine containers and cover with lids so bait won't dry out. (I have also used berry containers with success).
Place containers where you see ants. Ants may increase in number initially, but will disappear within days after worker ants carry boric acid back to nest. For long term control, reduce boric acid from 1 tsp. to 1/2 tsp.