Cover your food. First and foremost, never leave food out on the counter and always sweep the floors and wipe the counters free of any crumbs. If you have cereal boxes, put them in plastic, airtight containers. If you have rice, place it in a container as well. Food attracts mice. Don't let them sense you have it.
Soak cotton balls in essential oil and peppermint extract. Place these cotton balls near the entrances to your house, in your attic, and in your basement. They are nontoxic to you, and the peppermint smell repels mice. They hate it.
Place moth balls strategically around your house. Mothballs are toxic to humans and animals, so only place them where children and pets can't get to. Attics and empty basements work well. The smell is hideous to a mouse.
Plug in a sonic pulsator. You can purchase these at any home improvement or discount store. They send out sonic pulses that are meant to repel mice, ants, spiders and other creepy crawly creatures.
Walk around the outside and inside of your house and plug up any visible holes with caulk. If there is no obvious way for mice to enter your home, less mice will come in. Of course, some will find a way in, but that is what the mothballs, peppermint and the sonic pulsator are for.