Have you ever wondered why dogs have cold, wet noses? It might seem strange for a warm-blooded animal to have a cold, wet nose, but it's actually a fantastic adaptation that supercharges a dog's sense of smell and helps to regulate their body temperature.
Cold nose and sense of smell
A dog's nose is covered in a thin layer of mucus, which keeps it moist. Why is this helpful? Smell molecules travel through the air, but are easier to capture when they can attach to something, in this case, the moisture of a dog's nose traps tiny smell particles.
Moisture evaporates, and it is the constant evaporation of moisture from the surface of a dog's nose that makes it cooler than the rest of its body.
Dogs can also smell independently from each nostril, which allows them to work out the direction of the smell.
Noses and themoregulation
Humans sweat to cool down, but dogs don't have sweat glands, so they have to cool down a different way. They do this by panting and using their nose.
Dog noses have lots of blood vessels close to the surface. As moisture on the nose evaporates, it cools the blood passing through the nose, which then travels back through the body, helping to cool the body.
Heat detectors
Dogs' noses also act as heat detectors. They can detect a small animal from its heat from about 1.5 metres away. This only works because a dog's nose is cooler than the object it's trying to detect!
A dog's cold, wet nose is a great evolutionary adaptation with multiple uses, supercharging their sense of smell, helping to regulate their body temperature and allowing them to detect animals even when they can't see or hear them.
References
https://www.sciencefocus.com/news/dogs-cold-noses-are-ultra-sensitive-heat-detectors
If you enjoyed this, don't forget to take a look at my other science questions for kids!
Last Updated on January 26, 2026 by Emma Vanstone
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