[Jason Green]

Does he have a full coat of hair? If not - and genuinely seems happier to be with you, then maybe he now thinks that being kept by you is how it should be.

When new posters say they've found a young blue tit, I ask if it's calling and they've said it has been - then I've encouraged them to release it safely AWAY from cats etc, and the parents in this particular case actually returned to their juv and began feeding it. By the next morning it had dissapeared along with them! In cases like this where no injury seems apparent I always encourage people to return it to the wild ASAP.

However, in this case it seems young and we don't know for sure if the parents will accept it, it having had contact with humans - for good reason. I therefore think MAYBE the mouse would be safer looked after, at least for the time being. Afterall, if it IS this young if MAY not survive alone. It does seem to be happy, feeding etc, and most importantly SURVIVING. As it gets older or appears stronger, THEN try and release it again.

I have no real experience of having done this personally and I'm sure there are people on this forum who have, who will be able to advise. This is only my opinion.

Please post a pic and keep us updated!