Please DO NOT use poison!
Use snap traps. My lovely kitty had to be put down last month because he got into the neighbors open garage and ate rat poison. It's highly addictive.
Not only that, but it takes days to actually kill mice/rats. It's slow and painful, and it paralyzes them, and slowly shuts down their brain until they die. And think about the cycle:
Mouse eats poison, owl catches mouse. Owl dies, crows/foxes eat owl, they die, Ect, ect, Ect. The cycle goes on.
Please don't use poison. Use snap traps.