We all have a unique, natural smell- just like fingerprints except for identical twins. For this reason, body odour has been considered by some to be useful in biometrics. This distinct odour is sometimes referred to as the 'odourprint'. It is the reason why dogs can smell and track fugitives. Your scent also determines how attractive you might be to mosquitoes.
The genetic make up of a person is responsible for their distinct smell. Identical twins are known to share the same DNA, making them share a similar smell. A study in Switzerland showed that identical twins had a similar odour when compared to unrelated people. In another study published in the Oxford Journals, human sniffers were able to match the smell of identical twins even when the twins lived apart.