I used to have a rodent problem - in a couple of places I have lived - (mostly mice - but I'm fairly certain a rat or three was involved back in Crudsville!) In my expoerience you rarely have a 'mouse' to get rid of...it is more than likely 'mice' and if you don't see to it quickly it becomes more mice! Spring traps are cruel and I would never, ever use one. The tip-trap is more humane - but mice can die of fright in them. If you succeed in catching one, you can't simply let it go outside - they come back! You need to take them a good way away. Make sure the trap is situated sensibly - mice are clever little b*ggers and learn to knock them over to be able to get the treat. Place them against a wall. Buy two or three different models so that there is less chance of the mouse learning how to trip them all safely! Sadly, if you have more than one mouse and can't catch it quickly, then you might need to contact some form of rodent control - and that will mean poison and killing the mice.