This spring we bought our daughters a kit to raise butterflies from caterpillars. The whole process went well and 9 of the 10 caterpillars successfully turned into butterflies (Painted Lady I think). The 10th formed a chrysalis but never emerged.
The kids liked it so much they asked me to order a refill of caterpillars to do it again. But this time it hasn’t gone so well. All the caterpillars did their thing and started making crysalides. In one jar (which had 5 caterpillars), I first saw three chrysalides hanging and the two remaining larvae still walking around. A few hours later when I checked again, I saw a fourth caterpillar in a chrysalis but two of the other chrysalides had fallen. I thought this was odd. But then the same thing happened in the second jar. Four caterpillars formed chrysalides at first with one larva remaining (it was much smaller than the others from the beginning). A couple of days later I saw that two of the chrysalides had fallen. I think the 5th caterpillar did it. I should add that the jars have not been moved in any way during this whole time.
So all I can conclude is that the caterpillars that were still in larva form had accidentally/deliberately knocked down the others once they were in their vulnerable chrysalis state.
Is this a thing?
On a related point, is there anything I can so to save the chrysalides that have been knocked down?