Human Senses 1. Smell and Taste (15 of 21)

Human Senses

Smell was the first sense our animal ancestors developed.
But as we evolved in to humans our sense of smell got worst.
For a start our noses are too high off the ground.
The best sniffers keep their noses low.
Because smells sink down through the air forming an invisible fog just above the ground.
As well as being to high off the ground compared to some animals our noses aren't very sensitive.
Yet our noses work in the same way as a dogs.
The main difference is just the size of the snout.
Dogs have around 220 million receptors for smell; we have a mere 1 0 million.
Bloodhounds can track people days after they've walked by.

They can smell the minute traces of body scent which have seeped through the soles of the shoes and lodged on the ground.
For us to smell as well as a dog can, we'd need to have a muzzle as large as theirs.
But even with our limited sense of smell, bad odours are capable of giving us a real jolt.
We've come to Africa to sample a stench which more than any other has the ability to evoke the most stomach reactions in us.
Flesh that has been left rotting in the African sun produces a really awful smell.
urgh.
Spotted hyenas are one of the worlds must impressive carrion eaters.
They have a fantastic sense of smell and they're not put off by the smell of a rotting carcass that we'd find so disgusting.
In fact it's crucial for their survival that they like it.
Yeah in fact l've seen these guys follow er a smell up to shoove, 20, 30 kilometres, you know.
er, this is like a fillet steak for hyena.
You can see its not like they're just er are eating it cause they have too.
They're eating it cause they want too.