28/10/2026
Why dogs sniff, and what the nose is doing on a walk
If you've ever stood by a lamppost for what feels like five minutes while your dog investigates one small patch of grass, you're not alone. It can feel as if the walk isn't going anywhere. For your dog, though, this is the walk.
A dog's nose works very differently to ours. They have somewhere between 100 and 300 million scent receptors, compared with around 6 million in a human nose, and a much bigger share of their brain is given over to making sense of smell. Each nostril takes in scent separately, which helps them work out where a smell is coming from. When they breathe out, the air leaves through the slits at the sides of the nose, so it doesn't blow away the scent they're reading.
So that patch of grass is closer to a noticeboard than a patch of grass. Who has been past, how long ago, and something of how they were feeling. Your dog is catching up on the news of their neighbourhood.
Sniffing matters for how your dog feels, too. It's a natural, self-paced way for them to take in their surroundings, and many dogs visibly settle after a good sniff. One 2019 study found that dogs who did regular scentwork became more "optimistic" in how they responded to uncertain situations than dogs who did heelwork instead.
