Ticks are economically important ectoparasites and vectors for diseases such as Lyme disease, Rock Mountain spotted fever, and tick-borne encephalitis. Ticks are on the rise – population size and distribution has doubled in the last ten years. One possible control strategy is to interfere with the tick’s ability to locate hosts. However, tick neurobiology has been strongly neglected. The sensory and neuronal abilities of ticks remain mysterious. Ticks can detect a multitude of host-emitted sensory cues, such as body odor, CO2, moisture, heat, vibration, and visual stimuli. Exhaled CO2 seems to be a critical behavioral activator and attractant for ticks. However, CO2 is omnipresent and a nonspecific cue, bearing only limited information about host location and identity. The driving hypothesis of this proposal is that, like in mosquitoes and parasitic nematodes, CO2 detection potentiates attractiveness to other sensory cues such as body heat and host-specific odors. I will employ new behavioral assays to study the mechanisms for synergism and potentiation between CO2 and body-heat. Furthermore, I will identify and genetically manipulate receptors and channels presumably involved in tick CO2 and heat-detection. My studies will provide novel insight into the currently enigmatic tick sensory neurobiology and will help pave the way for the development of innovative control strategies.