Poisons and traps CAN work, but they are only solutions AFTER the fact, i.e. AFTER mice are already in your home.
The most important thing is to close up openings FROM THE OUTSIDE TO THE INSIDE OF YOUR HOME, -TIGHTLY!
That means that holes WITHIN your home (like where pipes under your sink go in the wall, are NOT important. If you closed a hole like that, and a mouse got UP TO where you closed the hole, he is ALREADY in the house, and will come out somewhere else.
Check to see that your doors seal COMPLETELY FLUSH with the floor.
Believe it or not, if you can slip a credit card under your door, a mouse can slip in. Go to a good hardware store and buy what is called a “door sweep” to attach to the bottom of the door. Make sure you attach it so it touches the floor, or you have wasted your time and money.