Pharaoh and thief ants appear identical but require slightly different extermination methods. Both require extermination using ant bait that the ants will carry back to their nests. Ant baiting involves disguising poison as food so the ants will carry it home to feed to the other ant workers and the queen, thereby destroying the entire colony. Failing to eliminate the entire colony at once results in more ants. Pharaoh ants bud off into separate colonies when they sense danger. Use the following steps to get rid of both pharaoh and thief ants at the same time, or separately.
Cut off the ant's access to your home. Look around your home for areas the ants use as entrances. Plug all sinks and drains when they are not in use. Use caulk to close any holes in walls, and around windows and doors that allow ants to invade your home.
Eliminate the ant's food supply. Store food in containers the ants cannot get into; place cereals and crisps in sealable plastic containers and eliminate crumbs and food residue by wiping counters often.
Place ant bait in areas the ants frequent. Pharaoh ants commonly travel along the edges of rooms, in corners and along baseboards, while thief ants frequent cabinets, closets, windowsills, trash bags and woodwork. Use high-protein ant bait or make your own ant bait from 1 part boric acid combined with 2 parts sugar and just enough hot water to dissolve the two powders. Combine this homemade ant bait with food grease to attract the thief ants that commonly feed on greasy foods, rather than sugary foods.
Resist the temptation to squish or spray the ants when they show up at the bait. Remember that you want the ants to carry the bait back to their nest to poison the entire colony and the queen. Continue to replace the bait for up to six months in areas that your pets cannot enter. Pharaoh ants take longer to eliminate than thief ants, so keeping the bait in place for six months, even after all signs of ants cease, effectively eliminates pharaoh ants.