Just when you thought dogs’ noses couldn’t get any more incredible — in some cases they can sniff odors at up to a millionth of the concentration we can — it now turns out they can detect heat, too. It helps explain why even a dog with compromised sight or hearing can find prey. They can sense the body heat of small mammals.
A team of Swedish and Hungarian researchers made the discovery when they trained three dogs to successfully choose between warm and room-temperature objects that were placed 5 feet away but that they couldn’t see or smell. They also looked at 13 dogs’ brains via magnetic resonance imaging (MRI). That part of the canine brain that receives information from the nose became more bright in response to a warm stimulus than to one at room temperature.
Dogs’ heat-seeking nostrils are apparently related to differences at the tips of their noses, called the rhinarium. More than for other mammals, the rhinarium is filled with nerves, allowing their noses to pick up not just odors but also weak thermal radiation.
Dogs aren’t the only animals that can “smell” heat emanating from other bodies. So can black fire beetles, certain snakes, and vampire bats.
