Sounds like they got into the attic. If it's accessable, you can probably find a duct hose with a hole or a duct without a hose or where they gained entry up there. you might consider getting a cat to get rid of them!
When mice smell other rodents or pets they can chew trough the wood or plastic and if you use mouse traps more mice will come because they smell the animal that died in the mouse trap but mice are quite smart these days so sometimes they know what the mouse traps do...
-SycoBob
Generally a small hole or gap near the bottom. Under a door is common, also homes with an attached garage are especially vulnerable. Once they get in there, guess where they go next?
Gas them.
you can set mice traps around the house or if that dosnt work you can call an exterminator company to get rid of them :)
you cant
It works to get rid of diseases in the air, while acting as expectorant. The mice do not like the smell of wintergreen or peppermint.
One way to get rid of field mice is to use poison.
A person can get rid of mice in a basement by setting up discreet yet effective mouse traps. Also, take care not to create a comfortable environment for mice to breed in your home.
Get the dead animals out of your heater ducts.
get a cat
Hide them under your matteress.
poison them
The mice hit Dogzilla with a blast of warm, sudsy water.
Get a cat or a rat snake or some poison.
You can always put of mice traps. Or go to walmart and bye the insta kills. These are just a few easy ways that you can get rid of them. But if the problem exceeds then a professional must be called.