Taking the idea of plant movement a little further -- do you know if there are such things as time-lapse photos of semps? I've seen some of other plants and they look sometimes almost as if they are dancing. Semps seem more literally "stuck in the mud," rigid or maybe even static, but I wonder if they may have a secret life that would only show up with a time-lapse "movie?" Probably not really important -- just curiosity -- but then that's what got me into this forum in the first place!
