Common mistakes with do it yourself pest control are poor placement of traps and using too few of them. Mice have poor vision and prefer to feel their way along walls. Place snap traps along walls in areas where you've seen the telltale brown pellets. For an average-size house, two dozen mousetraps would not be too many.
The best technique is to set two traps, parallel to the wall, with the triggers facing out. While mice can jump over one trap, they can't jump two. Favorite baits of professional exterminators are chocolate syrup and peanut butter.
Live traps are best used in pairs in the same manner as conventional mousetraps. Place them back-to-back with the open doors on each end.
TIP: Before you sweep up mouse droppings, always spray them with a disinfectant spray such as Lysol. Mice can pass disease to humans through their waste.
How Common Household Pests Get In
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.