re: Hatchings
The babies I spotted were only one half to three quarters of an inch long. Identified them by their claw-like forearms, which was cool.
I was struck by this one mantis who was around my jade bush all last fall, and I found it right on my door mat one morning after the first frost. Brought it into the house and put him on a jade plant, and fed him spiders or crickets or whatever I could find. Was fine until the cat got him. I think they are fascinating creatures when they look at you.
And someone last year posted a video of a mantis catching a humming bird in flight. Amazing.