In this recording the cactus in the middle (by this time known as "Clive") stayed asleep for nearly four days before joining in. Although one plant appeared to plant his face in a bowl of water, we think this was more by accident than design as the others didn't seem too bothered by them.
I have potted up one large plant into a pot on it's own to see if they behave any differently away from the group. But it's now getting into the dormant period for cacti so I won't make a further video until next year. In the meantime I have a tray of rooted cuttings to plant out with the others, partly out of interest and partly to keep them all company.
Without making a timelapse of the entire cactus house I can't say for sure that it's only this species that move in this way, but this is the only one we've observed so far. We will publish any further findings as we make them.
Ziggy Searchfield. Member of the Dover Branch of the British Cactus and Succulent Society.