bbc: Field mice is a kinda generic term. Some of those field mice may be deer mice, and they carry disease that can be very dangerous to humans. (Parvovirus.) Basically, the infection can spread to humans from the droppings, saliva or urine of the mice.

Wear a face mask--dust mask from a hradware store of the kind used by drywallers, when you handle the things, dead or alive, and latex gloves to clean the messes you find. Use a bleach solution.

Live trapping the cute little things will not do you much good if you don't take them far away for release. They reproduce fairly quickly, and there are LOTS of them, so don't feel you'll damage the ecosystem by killing a few tens of thousands.

I have lived through a "field mouse" infestation. Take it seriously. You may have to kill gangs of them, like it or not. Alternative is to get a cat. That will help. But use the traps, too.