If these were shrews moles or voles you would probably think it was interesting to see, but a mouse that's a monster !
Are they house mice or field mice? Quite often they are field mice that come in from the gardens, when it has been very wet and their little nests get water logged.They usually disappear again of their own accord, BUT.. I had them last winter, (their nest had been disturbed with gardening work). Using the humane traps and a few snickers bars was fine. To put them back into their society, you have to take them a long way away, so they don't find their way back. Nightly walks to the bottom of the garden was not proving successful, it was not far enough.They were beginning to take up residence and so I thought it best to use poison and dispose of the family that had moved in, before anymore appeared. It seemed a less cruel option. Take the few to save the many.
So sad as it seems, quick action I think is better than delayed action. Sorry little mice please forgive!