Q: Our dog will sometimes come into the bedroom and be startled at the sight of herself in our mirrored closet doors. Sometimes she'll even bark. Other times she takes no notice of her reflection at all. Does she recognize that it's her? Or think it's another dog?
A: The answer is actually a little more complex. In psychology circles, the mirror test is considered an important evaluation of self-awareness in animals and a sign of the normal development of cognitive skills in children. Humans are typically 18 months old before they are able to recognize themselves in the mirror. Among animals, only higher primates, dolphins, orcas, elephants and, surprisingly, European magpies are currently known to recognize that what they see in a mirror is a reflection of themselves. Even more interesting, perhaps, is that while pigs show no sign of recognizing their own reflections, they are able to use other information seen in the mirror, such as identifying the location of food placed behind them.
The animals who "pass" the mirror test rely on vision as their primary sense. When a cat or dog first sees his image in the mirror, he often reacts as if a strange animal suddenly appeared. But when the image doesn't pass the "sniff test," the pet generally decides to ignore it for good. As animals who rely more on their sense of smell than vision, dogs believe that when one contradicts the other, what the nose knows goes, every time.