Smelling
Different smells trigger different receptor cells in the lining of the nose. You can detect around 2000 different smelly substances or odorants. Most smells are a mixture of several odorants. Our ability to detect all these odorants varies - one in a thousand people cannot smell skunk odour. As well as the smells you are aware of, some scientists believe you can also detect pheromones, 'attraction chemicals'.
