I hate to use mouse traps, but can't afford an exterminator. It's not unusual for mice to invade a home and especially in the colder winter months. When you're lying awake at night and you hear the scampering in the walls or ceiling, you'll know you have unwanted house guests.
And yes, I kill them. Sorry, but that is the only way to rid them from my home. At first I bought a plug in sonic sound machine, that supposedly would drive them out, but they stayed. I bought traps that would catch them and not kill them, but they easily escaped from those. I tried to be nice and it did not work.
Even the cleanest of homes can have mice. Having cats may not solve the problem either. I have two cats, and one of them actually came nose to nose with the mouse, then turned and walked away!
An exterminator will cost money, and that is enough reason for me to get rid of mice myself. Traps don't include any types of poison and the animal is killed quickly. I hate killing animals, but the consequences of letting them have free roam is frightening.