I opened the back door the other day & spotted my cat black tom playing with something very tiny on the ground. Normally when I see him with a mouse, its fully grown & he usually growls & runs off with it, but sometimes he'll give me LIVE mice. Anyway, when he spotted me he proudly brought this tiniest little wee furred field mouse over & dropped it at my feet. It tried to trundle off in a daze & he caught it & returned it to me. When he does this, I normally give them a second chance, there are never too many mice around when it saves me paying for cat food as far as I'm concerned, but usually they die anyway. I didn't hold up much hope for the baby, but I brought it in (Cold, eyes closed, wet & shivering) & put her in the incubator. By her size & eyes I'd have judged her at 4 - 5 weeks or maybe 3 - 4 weeks. So I left her in the incubator for 2 - 3 hours with food & sugar water while I bleached down & set up an old small fish tank with sawdust from the chicken coop (I thought the outdoor scent would give her some comfort of home & the mouse was by the coop) & added food, water, toys & baby field mouse. And, just before anyone says too much about disease, I KNOW, I've raised field mice before, always wash my hands after petting, never handle them because this scares them & have never fallen sick from mice. Anyway, this little girl (Of course I have to sex everything that comes through the door) is an absolute sweetie. She will nibble bread from the hand & let you pet her at the same time. She comes out & runs around her tank, but only at night. She's got loads of hay to tunnel through. She's made a nest & has been hoarding her food in it. I've given her sticks & an old loo roll to play with to. But I do worry about her needing the company of another mouse, I'm hoping she may be older than I think she is & pregnant so I can cull the babies for cat food, but keep behind 1 or 2 girls as company for her. I don't think she would get on with a pet mouse I'd hate for her to kill it, vice versa or something. They are descended from house mice which is a different species. I would release, but now I know its a female, I'm a bit dubious about letting it go back in the yard & I don't wan to release her a mile away on strange grounds with no hiding hole & lots of competition from other mice. I'm thinking just let her be as long as she seems happy enough, but I sure would like her to have some company.