Ants in the Crib

Earlier this week we noticed a few ants in David's crib. I washed the sheet and put another one on. Well, we still found some ants. We proceeded to wash the sheet, mattress pad, bumper, dust ruffle, quilt, and everything else associated with the crib. We then moved all of the furniture our of the room and vaccumed the whole room- including the mattress. This was 2 days ago. Today when I got home from work I looked in his crib and there were, literally, about 50 ants in his crib. I've scheduled an exterminator. $124. Wow, home ownership is expensive! (and $124 is a discount because we already get termite service through the same company). I just hope the ants go away!! Anyone have any suggestions? Also, David never brings any type of drink or food in his bed. Or even in his room for that matter. The carpet, I'm sure, does have remnants of many throw ups and spit ups.