A taxis (plural taxes, pronounce /ˈtæksiːz/) is an innate behavioural response by an organism to a directional stimulus. A taxis differs from a tropism (turning response, often growth towards or away from a stimulus) in that the organism has motility and demonstrates guided movement towards or away from the stimulus . It also differs from a kinesis, a non-directional change in activity in response to a stimulus that results in the illusion of directed motion due to different rates of activity depending on stimulus intensity.