If they're living outside in the bank then they're not house mice and they're nothing to worry about. They may be field or wood mice and could come indoors in cold weather, but there's no reason why they should.
We occasionally get house mice that have migrated from the often empty house next door and they're very different from the ones in your photos. They get short shrift.
More often we get field/wood mice (large heads compared with their bodies unlike house mice which are bigger anyway) and voles (very short or no tails) brought in by the cats. They don't want to be indoors! So we catch them in humane traps and put them out again. There must be hundreds of them around us but they've never come in of their own volition.
Please don't kill them if you can help it - they're cute little wild creatures that need preserving. Watch them through the window and enjoy their antics.