Natural bug repellents are useful inside and outside the home. Pungent-smelling plants like mint and rosemary ward off insects and double as cooking herbs. Lemongrass and geraniums contain Citronella oil, which bugs hate.
Fighting insects with their natural enemies, a concept know as integrated pest management, limits their population. Many common songbirds love to eat insects. Encourage sparrows, cardinals and chickadees to flock to your home with suet cakes -- special varieties won't melt in warm weather. Encourage them to stay by building them a birdhouse. Welcome (within reason) spiders, bats and geckos. One gecko has the same bug-killing potential as an application of insecticide.
If you don't mind getting rid of the critters yourself, sprinkle a mixture of equal parts borax and sugar where ants gather. The stuff will kill them, but not before they share it with the rest of the colony. A type of soil called diatomaceous earth, sold in gardening shops, contains slivers of tiny shells that actually cut bugs. A solution of liquid dishwashing detergent and water is fatal to box elders and Japanese beetles. Don't spray plants, though, because detergent will damage them, too.