If the mice nested somewhere in your coach you could have a dozen of them or more in there. I use electronic sound determent devices. I use two devices and I have them plugged in 24/7/365. I also make it uncomfortable for rodents to get around in the my coach I've opened every drawer to find cubby holes and passage ways where they travel and filled these areas in with very coarse steel wool. I only use bait traps when I know rodents are in my coach and I have to get them out! If there is no rodents in my coach I don't use bait traps because I do not want to attract rodents into my coach. Rodent entry points, for example, I'll use a large rat they can enter your coach in a space the size of your thumb, due to they have collapsable spines. Good Luck on whatever you choose to use.