What Do Animals Know About Death? By Jennifer Szalai Our neighbor’s cat, Mittens, was an adventurer who used to sneak into our house whenever the opportunity presented itself. When he went missing a few weeks ago, our own cat started behaving differently. Usually silent and regal, she became clingy and would wail while she stared out the window. “She’s in mourning,” my husband said. We assumed Mittens was dead. Did our cat “assume” the same thing? Talking about animals and mourning invites inevitable charges of anthropomorphism, that tempting habit of projecting human characteristics on to a nonhuman animal. But as Susana Monsó explains in “Playing Possum: How Animals Understand Death,” our fear of anthropomorphism can lead to the opposite sin of “anthropectomy” — the denial that an animal exhibits humanlike characteristics.