Do we?
Keep finding the dead fuckers everywhere. Cat is a great mouser and loves to bring them home to us. No evidence of droppings anywhere, no scuttling in the night, never seen a live one.
But since autumn we've found one dead somewhere on an almost weekly basis. This is out first year in this house and DCat did bring us presents in the old one but not so frequently 
It's is an extremely old house, double cellar and chimneys in every room, they wouldn't be in the chimney would they? Surely we'd have heard them if so?