Dry on the left, humid on the right. Watch whether the same starting scatter clusters in the humid zone through undirected turning-rate changes (kinesis) or direct steering (taxis).
In humid half (right): 50% of individuals
Kinesis: turning rate and overall activity (including brief pauses) are high in dry conditions and low in humid conditions — no steering toward humidity, yet individuals still end up concentrated there because they simply move around less once they arrive.