Why do dogs sniff everything?

1. 1

   Lue says

   Everyone who walks by leaves tiny bits of themselves behind, like skin flakes and sweat. Those bits give off smells too faint for you to notice. But a dog's nose can pick them up, even hours later. So when I sniff the floor, I'm finding out who came past and which way they went.

   For ages 4–7
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   Checked against How your dog's nose knows so much (KQED Deep Look)

2. 2

   Why is a dog's nose so much better than mine?

   Inside a dog's nose, the air splits two ways. One path is for breathing. The other carries smells deep into the back, where the smell catchers are. The smells stay put there, even while the dog breathes out. When you breathe out, your smells blow away. So a dog keeps hold of smells that you would lose.

   For ages 6–9
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   Checked against Conan's Umwelt: how a dog sniffs (National Geographic)

3. 3

   Why do dogs sniff in quick little puffs?

   Look closely at a dog's nostrils. Each one has a little slit at the side. When a dog breathes out, the old air whooshes out through those slits, back and away. That helps pull fresh air in at the front. So with every quick sniff, new smells keep flowing in.

   For ages 8–11
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   Checked against How your dog's nose knows so much (KQED Deep Look)

In Lil' Phil, reaching the bottom of this wonder earns a sticker for Lue's collection.

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