Fortunately that clump has lots more scapes, and I haven't seen other buds on the ground - I guess that leaning scape on the outside of the clump looked worth a try and was easy to reach. I suspect (hope!) it was just a youthful experiment and it discovered it didn't like them. There are certainly plenty of rabbits around and plenty of daylilies that have only been attacked by deer up to now (or they'd have to have been bunnies on a trampoline or with a stepladder
). I'd never have realized it was a rabbit that did it if I hadn't seen it happen.
I think these young bunnies lost their mother on the road as I used to see them with a parent, but not since an adult bunny was a traffic casualty nearby.