I have 2 cats and a lovely old visiting cat who comes in to sleep sometimes. (I don't feed him)
My neighbours have 2 un neutered young male cats. One has taken to coming in. This started in the summer when I had the back door open. He eats anything he can get his paws on - butter, stole ham when I was making packed lunches (I went to tge other room for a minute) he's pulled the cling film off a plate of cakes abd eaten them. Knocked a tupperware off and opened it and eaten biscuits, leftover sandwiches, and so on. Sometimes it's only minutes that I leave the kitchen and he's been in. This is annoying, as he also walks all over the surfaces in the kitchen (my cats dont) literally leaving muddy footprints.
But, he's started weeing. On the hall carpet, up the kitchen cupboards, and today, on my DC pe bags.
He is breaking in through the locked cat flap. I locked it a few weeks ago to try and prevent him getting in thinking if he couldn't get in for a few weeks he'd give up.
I am making a point of never leaving any food out but often there will be cat biscuits (feed my cats, they'll eat but leave a few).
What on earth else can I do?? Whenever I see him, I throw water and chase him off.