How can some animal smell something so farrr away like a few kilometers away?

Question

I just never understand how it works

In: Biology

Answer 1

I actually wondered that before.

Like dog I get, as particles can waft around in the air very far.

But like shark? If you are bleeding , it isn’t like your blood particles get very far in the water like in air very fast.
Yet they can still smell it from a mile away?