Wow, what a difference a 3-day weekend makes - we left Friday with 2 chrysalises and come back to 27!! There are also still about 40 caterpillars munching away and getting bigger each day.
One thing we learned over the holiday weekend is what to do when a chrysalis falls. The chrysalis are attached to the ceilings and walls of the emergence chambers by a small silk button, woven by the caterpillar. These can be moved after they've hardened, about 48 hours, but should be left alone until that time.
So what happens when you find one on the bottom? This is a problem when the chrysalis is still soft. If left lying on its side then it can flatten and result in serious development problems. You should immediately re-attach the chrysalis to the side, either by attaching the silk pad to a cotton ball and hanging that, or taping the exposed silk pad to the side (don't tape the chrysalis).
For our trouble shooting we went with tape. The chrysalis silk pad wasn't really latching on to anything so we taped it to the side of an emergence chamber. Unfortunately we didn't have tweezers so we very delicately used our fingers on the surprisingly soft chrysalis. We hope this one pulls through!