Pharoah Ant
 

Found a few small ants in guest bathroom sink. Have been told these ants are Pharoah ants. From experience found that a small drop of a product called Ferro (Cheap) on a cardboard tab attracts the herd. Don't kill them but let them enjoy. 5 hours later , the herd has dispersed and is feeding the queen. These guys find the drop and then feed and then go back to nest to share. Follow the trail to eliminate by placing the drop in the right place