At ThatOne...
I've got an insane, psychotic, homicidal, DevilCat (but I repeat myself) that sits on my front porch. Anyone trying to knock on the door gets said demon rubbing against their legs as if it wants to be petted. The nanosecond you drop a hand towards the little mongrel, she turns into an industrial metal shredder with a taste for Human blood. Cue the fountains of ichor, arterial spurting, screams for mercy, & eventual sounds of a kitty belching in delight from it's meal. Then she cleans herself to remove the evidence that the knocker was ever there, climbs back into her favorite sunny perch, & takes a nap.
I had thought to get a security camera so I could ID strangers that try to knock, but all the footage I'm ever likely to find is the sort that turns the guts & might get used against me in court. I decided to skip the security camera. Now I just wait for the screaming to die off & look through the side window to determine if there are any packages I might like to retrieve before El Diablo wakes up...
If you'll excuse me I've got some flesh wounds to bandage before I bleed to death. I took too long giving Her Majesty Her kibble...