Automated-recording device for quantifying the selected host-seeking behavior. (A) Schematic view of the recording device to quantify mosquito activity patterns (see Materials and Methods). (B) An example of the selected host-seeking behavior of 60 female mosquitoes monitored for a short period (75 min) by automated-device shown in (A). CO2 was delivered for 2 sec at 15 min, 30 min, and 45 min (arrow). Note that female mosquitoes show "touch-down" behavior (blue) on the Peltier plate in response to the change of CO2 concentration (red).