This was a one time deal when a group of chicks were still behind divider wall.I have close to sixty birds do it every evening for almost 2 months. Revisit materials your birds come in contact with. Mine have plastic gutter guard tightly bound to pieces of plywood. Whatever you are using, trash it.
One bird got spooked.
Hasn't happened since, and have used same wall with chicks for 5 years since that incident.
Doesn't need to be 'trashed'.