科学百科：嗅觉最灵敏的动物是非洲象

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