Although your walls may appear solid, many walls are full of tiny pest passageways. Small insects can sneak through the tiniest cracks, so you may not be able to make your home absolutely bug-proof. But you can seal most gaps, especially the larger ones that let in mice and larger insects.
Put on some old clothes, as you'll have to get on the ground, slink behind bushes and even crawl under your deck to examine your home's exterior. Take a flashlight and a mirror along. If mice are your main concern, also bring a pencil. If you can slide the pencil into a crack, it's large enough for a young mouse to squeeze through.
Take your time and examine every square foot of your home. The key areas to inspect include wall penetrations, doors and windows, the foundation, dryer vents, exhaust fans and roof vents.
