The copepods were filmed for 10 minutes with a Viewpoint Zebralab behaviour analysis system with a dragonfly firewire camera. A number of activities (unitless) were automatically quantified in real-time by the Zebralab software: total activity, number of stops, freeze duration, medium speed count, medium speed duration, burst speed counts, and burst speed duration. The behaviours were averaged for every minute of the experiment. The total swimming activity is the total change of pixels over time.