There's loads of anecdotal stuff on CC about mice. Try the Search box.
My personal, lengthy
jihad led me to these conclusions...
1) 'Humane traps' are useless
2) Poison seemed to be untouched. I tried four different ones.
3) Old school wooden Nipper traps are absolute junk
4) The Rentokil Advanced mousetrap is pretty good, mainly due to the hair trigger.
http://www.amazon.co.uk/Rentokil-Advanced-Mouse-Trap-Twin/dp/B000T5N0JE
5) What to use as bait is an endless subject of debate. Nutella, peanut butter, bird seed etc. Google the subject and you will come up with pages of advice.
6) Flush them down the WC.
GCHQ is probably monitoring this forum. When they break down the front door at 3:45 am, make them a nice cup of tea and get them to employ their Heckler and Kochs on the Real Enemy.