Smelliest mammal

The world’s smelliest mammal is unquestionably the striped skunk (Mephitis mephitis), a member of the mustelid family, which ejects a truly foul-smelling liquid from its anal glands if threatened. This defensive secretion contains seven major volatile and stench-filled components. Two of these substances, both sulphur-containing thiols, are responsible for the secretion’s strongly repellent odour, and are known respectively as (E)-2-butene-1-thiol and 3-methyl-1-butanethiol. They are so potent that they can be detected by humans at a concentration of 10 parts per billion – an incredibly low dilution that is roughly equivalent to mixing a teaspoonful with the water from an Olympic-sized swimming pool!