Boric Acid Insecticidal Dust is great for getting rid of roaches. Just put it behind your storestove, refrigerator, and dish washer and wherever else they may crawl and it will take care of them.
Also I spray around the foundation of my entire house with an all purpose outdoor insect spray each spring when the weather starts to warm up. That usually takes care of the ants for the remainder of the spring, summer, and fall.