Toby used to do that too!
When the house opposite was leased out to some US service personnel a few years ago, a lovely family move in - parents, three kids and a kitten called Winston.
At 6 am every morning without fail Toby used to go out, cross the road and sit on their doorstep - and shout until he was let in. (Bill said that his alarm clock was totally redundant...) When he was let in, he would go and eat Winston's food, play with Winston's toys,use Winston's litter tray, then give the entire house a thorough inspection. When he was through, he'd sit on the door mat and ask to be let back out. Go figure!
On the other hand regarding the catnip, my neighbour's cat, an elderly half-siamese called Wally kept on breaking into my greenhouse to help himself. One evening I found him on the patio clutching a stem of 'nip to his chest and totally out for the count...