Since getting our cat, other local cats have been visiting during the day. Ours is a friendly cat, so he's not fussed about other cats in the house but there is one in particular who spends a lot of his time here. The visiting cat wears a collar, so must have an owner, but scoff any biscuits left in the bowl and licks the remnants of meat from the wet food bowl. He sleeps on the sofa, usually for a good two or three hours a day. We've started removing any food when this cat comes into the house, but he seems content just to sleep here, get a few strokes under the chin and a scratch behind the ears, and then go out again. Do you think I should contact the owner and tell them what he's doing? There's a mobile number on his tag, but no address or name. I don't want to make it sound like we're being petty and he's not causing any trouble!