Friendly wild baby mouse in the house

Question
Hi Natasha,
We have had a little wild baby mouse living in our house for the last couple of days, we think he is about 3-4 weeks old based on pictures we have looked at online.
He seems to have missed the personal safety class at mouse school as he spends all day just running about in front of us and our dog (luckily she is a very old lady and is not remotely interested in him). He is allowing us to get far to close to him and im not sure what to do as im really worried that he is to young to be on his own.
I dont want to catch him and put him outside as I could be plonking him in someone elses territory (we have had some little mice living in our garden wall on and off) and also we have a lot of large birds visit our garden and have cats in the neighbourhood.
We cant really just leave him either as I dont think he is manageing on his own very well and my main problem is also that we have pet fancy rats and im terrified that he will go into there cage at night looking for food and that they will hurt him or kill him.
What do you think would be the best thing to do for the little man?
If you could give me any advice I would be very grateful.
Many Thanks
Sarah

Answer
Dear Sarah,

It sounds to me like you now have a new pet. Buy him a nice big tank (he will escape through wire)  with accessories, wheel, and give him lots of toilet paper rolls (if you need more, your colleagues or neighbors might be willing to donate). Mouse food, etc. You  may very well be able to hand tame him. Otherwise, if when he is bigger he spends all of his time trying to get out of the cage and won't be held, he will need to be released far away from your cats.

This seems to me to be the best option.

squeaks n giggles,

Natasha