Out of curiosity I bought a small container with two praying mantis casings and placed it in the garden. Today the nymphs decided to emerge and they did en mass. From what I read most won’t survive, but hopefully a few will reach adulthood.
Great catch, reminds me when I was a kid I saw the little brown cocoon growing on a twig and broke it off to take to school to see what the teacher thought it was. Got up the next morning and had what looked like hundreds of the little critters in my room.