You can’t do that to your little sister, especially this time of year. Jeez.
Kelly O—formerly a Stranger staff photographer, music writer, Drunk of the Week columnist, and more!—finished art school and a soul-crushing internship at a corporate advertising agency in Detroit,... More by Kelly O

Makes you wonder what the other cat did to deserve to be pushed down the hole.
I think the pusher is envious of the pushee’s beautiful coat. Hence the push. Once pushee is dead, pusher can have a nice blanket made from her pelt.
Cats are impulsive little jerks sometimes.
@4- You say impulsive, but I think the pushing cat clearly thought that out. I think “Cats are jerks.” sums it up. I love the little bastards, but only because I’m 15 times their size. If our positions were reversed, the average cat would torture a human to death for fun and then maybe eat us if it was hungry. Or just leave our corpse someplace funny.