The Kitty-Cat Diaries

So last night I'm sitting in my apartment and this weird cat comes right up to my little pet door and acts like he's just gonna come right on in and check things out.

And I'm like, "No! You don't live here!" and he scrams.

Makes me wonder what's going on when I'm not home...is there some kind of kitty commune going down in my apartment that I don't know about? Has my place become some sort of crash pad for wandering felines all hopped up on catnip and looking for a bowl of free munchies?

Am I gonna have to install some kind of paw identification system on the kitty door?