Once my brother was sitting on the settee and he was looking down and my Mum said "Jack, what are you looking at?" and Jack said "I am looking at a mouse because there is a mouse on the settee."
As we have guinea pigs we have a problem with mice because the mice come to eat the guinea pig food in the shed, and it is not because my Mum does not vacuum under the cushions as has been suggested.
At its worst we had to distract young guests with our conversation as mice ran across the floor so that they wouldn't see and tell their Mums and perhaps wouldn't be allowed to come again.
We used humane traps and let the mice free on the Common in a procession with somebody holding the mouse in the box.