Not sure exactly what was happening, but it was a couple of zebra wings hanging upside down, on what looked like a chrysalis. It may be that a new zebra wing had just hatched. Not sure what the other one would have been doing there.
@annepann@milaniet thanks Anne and Milanie. I was wondering if the one in the front had just hatched out. It looks like the chrysalis that they were hanging on. But not sure why the bigger one would have been there for that. I'll check it out in the next day or so, and see if anything is left.