In contrast, evidence with "Culex quinquefasciatus" mosquitoes shows that DEET may serve as a true repellent in that "Culex" mosquitoes intensely dislike the smell of the chemical. A type of olfactory receptor neuron in special antennal sensilla of mosquitoes that is activated by DEET, as well as other known insect repellents such as eucalyptol, linalool, and thujone, has been identified. Moreover, in a behavioral test, DEET had a strong repellent activity in the absence of body odor attractants such as 1-octen-3-ol, lactic acid, or carbon dioxide. Both female and male mosquitoes showed the same response.