Everyone usually says that they want a dog or cat or something. If they're a dog person, they have visions of a sweet dog meeting them at the door, a softly wagging tail greeting them. I think it's our desire to be missed ("oh, aren't I important!")
I'm presently housesitting the three dogs. And NOBODY mentions dogs' desire to kill sweet, innocent animals, drag them inside and seriously cause the gag reflex to go crazy as you STARE AT THE RIPPED OFF BIRD LEG on the blanket that the Boston was sitting on just a short time ago.
Thanks to my sister's boyfriend for getting rid of the evidence of Violence Against Birds.
I have visions of the owners coming back to a "Godfather"-like moment in their bedroom, but I don't dare look THAT hard for the rest of the poor feathered friend.