Sometimes our cat, Roxy, dreams. We see her trying to run in her sleep, or she'll twitch and make little noises, and occasionally she'll wake up in full fight, flight or freeze mode and bite whoever's closest to her. After she went missing outside for nearly a week, Roxy showed signs of having nightmares for many days afterward. I've often watched her moving in her sleep and wondered how cats, dogs and other domestic animals experience dreamtime.

Certainly we have experiences in dreams which don't make logical sense in reality, but which seem perfectly reasonable while we're having them. If the dreams are vivid and realistic enough, we may awaken from them unable to shake the feelings we experienced, and we sometimes spend minutes to hours afterward convincing ourselves it was only a dream, it wasn't real.

If fully sapient beings such as humans, with logical, rationalizing brains, have a tough time telling the difference between dreams and reality, what must the dream experience be like for our pets? Do they think of their dreams as being of a piece with reality, as "that one time I floated through the kitchen and attacked a giant piece of kibble?" Or do they remember dreams at all after they have them? We're not certain how animal memories of real events work, whether they fully remember past experiences the same way we do. It's an aspect of their lives that is largely opaque to us, even though they've lived and worked alongside us for centuries -- a reminder that, as much as we think we've discovered about the world around us, there are still plenty of mysteries to explore within our own households.

In any case, I hope at least some of Roxy's dreams are happy. She's a good beastie, even when she bites.