Suer worked with the African mosquito Anopheles gambiae, one of the primary vectors for the spread malaria in sub-Saharan Africa, and tested them against the smells in his lab:
Suer tested their sense of smell in the labratory by pumping additional CO2 into a container to simulate human breath, then added a high concentration of five different foot odors and found that the mosquitoes were unable to react to the CO2 for several seconds. The sole-ful odors actually stopped mosquitoes from sensing CO2 from breathing — which could be a reason why malarial mosquitoes divert when honing in on a person and move instead to the feet at close ranges.