Researchers may have solved one of science's great mysteries - why a dog's nose is cold. Scientists from universities in Sweden and Hungary believe dogs' noses are always cold because they act as "ultra-sensitive heat detectors". Dogs can sense the temperature of things before they touch them. They said dogs use their noses to detect changes in temperature, such as when predators or prey are nearby. Humans only know something is hot after touching it, often with painful consequences. It was believed that dogs' noses are cold to control and regulate their own body temperature.
Researchers did experiments on dogs. The dogs had to detect the temperature of different objects. Humans could only differentiate the temperatures by touching the objects. The brain activity in the dogs showed that they knew which objects were warmer than others. The lead author of the study said: "Dogs are able to sense the thermal radiation coming from warm bodies...and they can change their behaviour according to this signal." Scientists should now re-evaluate how animals hunt. Many predators may use heat-sensing abilities to track or sense their prey.