Avoid using insect sprays. Pesticides are the number two cause of household poisonings in the U.S., as people and companion animals breathe in the toxic air. The best way to keep ants out of your house safely and naturally is by using products you may have in your kitchen cabinets right now. Try pouring a line of cream of tartar, red chili powder, paprika, or dried peppermint at the place where you think ants might be entering the house; they won’t cross it. You can also try washing countertops, cabinets, and floors with equal parts vinegar and water. To keep insects out in the first place, fill holes and cracks in walls with caulk or white glue. Finally, probably the most important thing you can do is to avoid giving insects a food supply, by keeping living areas clean. Be careful to sweep up crumbs, wash dishes immediately, store food in tightly sealed containers, and empty garbage frequently.