House mice are attracted to a lot of the same things you look for in a home, so it's not surprising that they'll quickly move in with you whenever they're given a chance. However, evicting them again and making sure they're gone requires you to identify every nest and entrance point for a thorough removal. Baiting only works if you get the bait stations close to nesting points, and the first step to stopping entry is identifying the entry points. Start your search with the spots where mice are most likely to congregate to have the best chance at catching every last one.
House mice prefer warm temperatures to cool drafts, so it's not surprising that they prefer the attic to the basement. Attics are also full of insulation that the mice can shred and fluff up to line their nests and tunnel through for hidden pathways. Don't forget that your attic is also conveniently connected to practically every other room in the house, including the kitchen that's full of tasty food, through the ceiling, and in wall cavities. It's best to remove any stored items from the attic during the pest investigation process since they're prone to turning boxes of holiday decorations and family photos into nests as well.
Your refrigerator and oven are also wonderful sources of warmth and provide a convenient hiding place within the mouse's favorite room—the kitchen. It takes effort to gnaw into the back of a cabinet or a hole through the floor, but the gap between a large appliance and the wall provides a ready made nesting spot and walkway for the mice. It's essential to pull all of the appliances away from the wall, even if they're permanently attached, in order to check for nests and to look for holes and openings that are hidden by the appliances. Leaving a nest behind, even after every mouse is removed from the home, could cause a fire. If you don't notice any signs of mice behind the appliances, don't forget to check the back of the cabinets as well.
Inside the Walls
Mice may or may not build their nests inside your walls, but they're almost definitely using them as a sort of hidden and protected highway. Unless you've got an unusual building style that left your walls completely solid, mice can fit inside even the smallest gaps left between two rooms. Of course, there's so much space in between all of the walls of a home that it can be tricky to run cameras through all of them to look for nests and signs of mouse travel. However, it's well worth all the effort to actually look inside as much of the wall cavities as possible because it's a common hiding spot for mice who are trying to evade your attempts at pest control. Heat and moisture scans may provide better results without the need to drill even small holes for running cameras.
In Ceiling Cavities
Did you check your attic but find no signs of mice? Check if you have a separate ceiling cavity sealed between the attic and the rooms below it. These cavities are often built to create a better looking ceiling without having to demolish part of the room. The cavities are usually completely empty or filled with insulation only, so it's a natural place for mice to want to live. These cavities tend to be easy enough to check with thermal cameras, but are almost impossible to inspect any other way unless they're accessible from the attic. You'll usually see stains coming through the ceiling eventually if there are nests, but this takes months or years and shouldn't be relied upon for determining if pests are present.
For more information, contact a professional in your area or visit a website like http://www.dontgivepestsachance.com/.