In some situations, foot odour is much more serious than slight embarrassment, however – it might be a matter of life or death. Dutch scientist Bart Knols was one of the first to notice that certain species of malaria-carrying mosquitoes are attracted to the smells wafting from our feet. His work has since inspired many of Smallegange’s latest studies at Wageningen University in the Netherlands.

She has found, for instance, that the malaria parasite seems to alter the mosquitoes’ sense of smell so that they are even more attracted to smellier feet, swarming to worn socks like bees to a flower bed. “There is some evidence that some proteins in the head of the mosquito change somehow, and they have a role in the olfactory response of mosquitoes,” says Smallegange. It’s a devious mechanism that leads the malaria’s host to home in on potential victims, so that it can continue its life cycle in a human body. “It’s why the mosquito is such a good vector of malaria.”

There are many ways this knowledge could help the fight against malaria. Smallegange has also examined whether the particular combination of smell-producing bacteria on feet can alter your chances of being bitten; as you might expect, those hosting more Staphylococcus tend to be more attractive. Attempts to combat those bacteria could therefore offer some protection against the deadly disease.