First, let’s be clear about the difference between animals (things with multiple cells that eat and move) and mammals (animals that give milk--if female-- and have hair). Animals include worms, insects, fish, and many more species. You are probably thinking about the kinds of noses that dogs and cats and many other mammals have. Not all mammals have wet pink noses, but many do have hairless noses. This allows water to evaporate from their noses and cool them off. Noses can be colored dark by things called pigments. If they do not have dark pigments, the noses will look pink because they have a lot of blood flowing through them. This carries more heat to their noses. The blood can also warm up cold air that the animals breathe in.

Having a wet nose also helps mammals smell. When the tiny scent particles in the air are dissolved in water, they are more likely to set off the “smell detectors” in the animal’s nose.

Humans are mammals too, but we belong to the primate group that doesn’t have wet noses.

Can you think of other mammals that don’t have wet noses? Why do you think they don’t need them?

My dog had a wet black nose. She was a mostly black dog, with a little white. My tenants' dog is brown, and she has a brown nose. It's moist but not particularly wet. When dogs get a fever, their noses get hot and dry. A veterniarian on the internet said dogs' noses are wet because they lick them! If they don't lick them, they're not wet, and that's ok, too.

Keep asking questions! Best wishes,

The wetness nose covers the smell receptors and lets the animal smell more effectively. A better question is why other animals (like humans) have dry noses that do not smell so well...