Previously it was estimated that we could smell 10,000 odours but now researchers say it is more like one trillion.
Scientists believe our sense of smell is much closer to that of animals than appreciated, but we no longer pay attention because smells are often hidden, meaning that important information is lost.
Mammal Number of genes
Elephant 1948
Cow 1186
Dog 811
Horse 1066
Rabbit 768
Guinea Pig 796
Rat 1207
Mouse 1130
Marmoset 366
Macaque 309
Orangutan 296
Chimapanzee 380
Human 396
