i live next door to a large uncultivated garden ,recently i caught a tiny field mouse -in a humane trap and released it into the wild .i have just seen another one but that one is evading capture .i am terrified of them coming into my house as the weather gets colder .would field mice nest inside in the winter i havent got a cat and i dont want to get one.
Yes, they might come inside - if they can get in! I've never known field mice to actually nest indoors though - even in an unoccupied property. They like to come and go ... your best bet is to check your property and block up any gaps where they might get in.
I have much the same problem.. My neighbour is actually feeding the 'cute little mice' his words not mine!! I have even seen them crawl up walls so I have to keep my windows shut. I don't know if field mice do come in doors, I'm sure they would given half the chance! Someone told me when checking for gaps and holes round your house, if a pencil fits through the gap so can a mouse!
Good luck.