how to raise a baby fieldmouse

Question
Hi Tam,

I've just rescued 2 babyfield mice whose home had been destroyed & Mummy was dead =( They were very weak and cold but I think I have managed to nurse them back to health. We're feeding them warm puppy milk every 4 hours or so, which can be a struggle as they don't always want to take it, but they seem to be getting used to it. They are just over an inch big and still have their eyes closed but their teeth seem to be developing. We're keeping them nice and warm and they are managing to poo quite regularly!

I just wanted some tips on how to care for them from now on. Am I feeding them often enough? When should I try to wean them off milk? And what should I feed them when I try to do that?

At the moment we're keeping them in a box with fluffy socks to sleep in which they love. We've got a big cage to move them into when they get bigger but not sure when would be the best time to make the move?

Sorry for the long and complicated question, I just want to make sure we're giving them the best chance we can. Any other tips you might have would be much appreciated.

Many thanks!

Answer
Hi Kate,

Congrats on having successfully raised them thus far - the earlier days are the hardest!  Sounds like you're feeding them about right, but if they don't want to eat, you don't have to push them - as long as they do eat a few times a day and aren't losing weight.  They'll let you know when they're hungry.

You can start leaving mouse food (a mix made for mice, or rodent blocks) in their home now, if you'd like.  They will start exploring it and trying to chew it when they are ready.  Start without the seeds, since they will have a hard time opening them until they're a bit older.  You can also introduce a water bottle now, and they'll explore it when they're older, as well.  They will continue to need milk even if they're eating solids until you observe them drinking regularly from the bottle on their own.  By then their eyes will be open and they'll be pretty close to full-grown (about 3-4 weeks old).  You don't need to do anything except provide milk when they're hungry (at least a few times a day - watch to make sure they don't lose weight) - they will figure out food and water on their own as long as it's there.

Don't move them to the new cage until you're certain their heads cannot fit through the bars.  Once they start to move around and explore they can become quite mischievous, and you wouldn't want to lose one after rescuing them!  If you intend to keep them and not release them, it would be a good idea to verify they are definitely field mice and not deer mice.  Deer mice can carry hantavirus, which would not affect them but could be very serious to you, and is transmitted by their waste, especially when aerosolized (like from fluffing up bedding, for instance).  You can probably bring them by a vet once they're older and just ask for them to identify the species, maybe even without having to pay for a full visit.  I would help, but I'm rotten at identifying species from photos!  Only deer mice carry the virus - no other species of field mouse or any other kind of mouse can carry it.

Good luck raising them, it sounds like you're doing a terrific job!
-Tam