Conceal inhibitor resulted from cooperative research between the USDA Agricultural Research Service and BioSensory, which co-own its US and International patents. This USDA test illustrates the difference between a repellent, Deet, and an inhibitor, Conceal. Mosquitoes can attack human scent placed in either of two ports in a laboratory device. One port has only human scent. The other port has human scent protected by Conceal or by Deet. Notice that 14% of mosquitoes went to the port protected by Conceal, compared to 28% for Deet. Because Conceal impairs scent-tracking, another 28% of the mosquitoes didn't respond they never left the holding chamber when Conceal was used, compared to only 10% for Deet.