Neurological mechanisms 1. Stimulus filtering Most organisms filter out most of the stimuli that they are exposed to and respond only to the important stimuli. In cases in which you were exposed to a constant stimulus, your sensory cells began to respond less and less. The response was strong when the stimulus was novel. I also mentioned a couple of examples in other organisms.
Ticks have receptors that respond to light.
They crawl toward the light which means that they end up on the tips of vegetation. Once they arrive at this location, their response to light is diminished and they begin to respond to butyric acid. This stimulus will cause them to drop off the vegetation and hopefully land on a passing animal. Once they've landed on a host, they filter out nearly every stimulus except heat. This causes them to seek out the warmest spots on the body which tend to be little crevices where they will be harder to find.