Do you know that ants will not cross a white chalk line?
The chalk sticks to their tiny feet, and they avoid it at all cost. (The exception is: If you circle an ant with a piece of chalk, it will eventually cross the line and get out, but only with great difficulty...try it.) If you run out of bug spray, or can't afford it, just draw a white chalk line around your Big Mac, whatever, and you can leave it and return and not have to pick the little buggers off it when you go back to eating. You can draw circles around your bed posts on the floor if the little buggers are getting into your bed. You may get some comments from guests in your house: "What are those circles around your bed posts? Are you nuts?" You may have to redraw the circles, they get swept away in everyday cleaning.
Another trick, useful if you have kids, and pets, and want to avoid using chemicals of any kind is use the ants craving for sweets to your advantage. Take a cruet, or similar shaped jar, add a few tablespoons of sugar. Add some warm water and disolve by mixing or shaking. Just set the cruet near where the ants are giving you the most trouble. The ants natural sweet tooth will draw them to it, they will go into the cruet to have a drink, and end up drowning in it. Other ants of the same colony will follow, and meet the same fate either by trying to rescue their fellow ants, or by their own greed for the mix.