You have my sympathy - since I moved to East Dulwich every single house we've lived in has had mice! It's very upsetting when you have little ones. We tried everything but I'm afraid the only way to properly get rid of them is to blitz the place from top to bottom with industrial strength poison. Glue traps just catch them, then you have to do the killing yourself! Or let them starve, which stinks. We moved into our current house in December and there were droppings in the FRIDGE. We got pest control round who blitzed the whole house, and we've had nothing since. Good luck!