This is a video from insect lover and Youtuber InsecthausTV showing off a group of angry dead leaf mantises. They're angry because he pokes them with his finger. I get angry when people poke me too. Unless it's on Facebook, then it's okay because I know they just miss me/want to get in my pants (technically sweats I accidentally cut into shorts when I was weed-whacking) and aren't just hoping I'll giggle like the Pillsbury Doughboy.
Keep going for the video.
Thanks to Marcus O, who agrees those things are definitely aliens.