When it comes to noses, size is not important. We all smell things differently. It's mostly the number of nasal smell receptors and the unique combination of smelling genes that help us, and animals, smell odors. We learn how receptors in the olfactory epithelium send messages to the brain, bacteria that cause odours, bad breath, the relationship of taste and smell, creatures with smell sensitive antennae or suction cups, why a rabbit's nose twitches, elephant's amazing noses, and how sharks smell.