We Don't Know What We're Missing

One of my mother's dogs is ancient, almost totally blind and stone deaf. Nowadays, this dog spends almost all her time quietly and deeply asleep in front of the fire. The other night though she started to behave very oddly, unable to settle, yelping and crying inconsolably. Eventually, my mother let her out, hoping she would calm down.

The dog shot off into the darkness and wouldn't come back. My mother had to stagger about with a torch, looking for her. Eventually she found the dog, covered in mud and still acting as if possessed. She brought her inside and tried to get her to relax by the fire. The dog cried like a child and my mother had to get up several times in the night to see if she was all right.

My mother's efforts made no difference. The dog continued to behave as if demented - in fact, my mother began to worry that the dog was suffering from exactly that: a sudden onset of dementia from which she would never return to her usual placid self.

In the morning, however, the dog was back to normal and, going out, my mother discovered the cause of her night-time frenzy. There had been a kangaroo in the garden. The dog, whose life, deprived of sight and sound, we had thought so lacking in vivid experience, had clearly sensed the creature's presence, even though it did not appear to have come anywhere near the house.

Unlike us, mum's dog apparently lives in a universe where smell is as powerful a form of perception as sight or sound for us. What must it be like to be assaulted not just by light and noise but odours - and are there senses at work in the dog's brain that we can only guess at? Were there other signals, beyond mere scent, pulsing through the night air that she was aware of but that we are ill-equipped or unwilling to receive?