Live on the third floor of an apartment building and am having a problem with small black/brownish ants. I first noticed them on a chocolate spill that I did not realize was there (silly cats knocked over a beverage). I IMMEDIATELY cleaned the spot, followed their trail, washed the trail and baseboards and taped up the spot they were enteringing through. I was rid of them for a week, until I went into an adjacent room and I noticed they were coming in there! In this room they were just wandering, and I taped up what I perceived to be their entrace, cleaned the carpet anyway, and used pepermint extract on all the baseboards, walls, etc... Now I am not sure what is going on, I can't tell if the ones in the apartment are new or ones just left over. Some are VERY tiny and some are just small, which makes me worry they are babies. They try and disappear behind the baseboards and come back out, they don't seem to be eating just wandering back and forth to the exit site and back to the baseboard. So what I want to know is do I need to kill these few in the apartment, or will they just die on their own? What is anyone's assessment on how I can get rid of these things without hurting my cats? They seemed to be coming from OUTSIDE through a crack in the window and through an old not used window air.

First take a sample of an undamaged ant to your local entomology program at a university near you. Very important to identiy ant species.

Then try injecting bait into wall where ants are coming from these are not accessible to your cat. The bait must by labeled for your ant and changing from a suger to protein base (check with distributer)
Or combing both in you treatment stratgy will improve results. http://www.doyourownpestcontrol.com/SPEC/pick-antkit_1.htm