Richard A Downing wrote:

At least two, probably more. Also a word on Traps. The so called
'Humane' traps are the least humane things ever. Unless you can
guarantee to check them every 2-3 hours any mouse caught in one will
die in a horrible way.

It's what I use/used and the mice have always been perfectly happy the
following morning to be released. 'Course I made the initial mistake of
releasing them in the back garden, then across the road, and eventually
across the other side of the green I live on. Talking to professional
exterminator he reckoned if you're going to release them make it at
least half a mile as they will have found their way back to your house
in under five minutes. I compromised by releasing them somewhere far
enough away and hopefully more attractive. Not sure my neighbours liked
that plan though. Thankfully I haven't had to do it in over a year.

Regards

Mark