Help! My cat is more antisocial than usual.

Factual Questions
1

Since spring has sprung, we’ve been leaving the door open, with the screen door closed. Our cat, neutered female, strictly indoors, is very excited by the birdies and whatnot. She freqently hangs out around the door, standing up on her hind legs and looking out, her tail curling and uncurling contentedly. Cute enough to go on a greeting card.

This morning, after sniffing around the door, she became psycho kittie from hell, tail fully-poofed, hissing, whapping at us, and making the long, low, I’m-extremely-pissed-off meow.

There are some other cats in the neighborhood. Could they be spraying around the door, or something?

Any hints or suggestions?

2

Sounds like that’s exactly the case. You probably had a stray or neighbor cat come around, smell your cat’s scent by the door, and spray the area on or around your door. Your cat probably got a whiff of this, and decided that it was an invasion of it’s otherwise firmly-defined territory inside the house. This reaction is pretty standard, and the spray scent will fade after a while. Your kitty should be back to her normal, loving self after a short while.