We left out biscuits and they started going and one day all 4 bowls were demolished but......when I put a camara out to check it turned out it was a great big rat taking the biscuits and not the Cat or his mates.One of our cats (Jasper) did that. At about a year old (and yes, he’d got his bits chopped off), he just started upping and leaving. We always left out biscuits, and I’d sometimes catch him stuffing his face in the kitchen, in the middle of the night. This all went from a week away, to 2-3 months at a time.
We were so convinced that he would eventually not bother coming back, that we took on a kitten from the cat rescue. Another 2 months passed, and Jasper walked in, saw the kitten, and never left home again. Not that he loved Toby, in fact he hated him from day one, but I think Jasper felt he was in danger of losing his expedition base if he left home long term again.