A Facebook post and some pictures on the Knob Noster State Park proclaim that the aliens have landed! And the pictures shared by the park certainly show these alien-looking gross things on tree trunks. But, no, it's not anything alien at all. It's just cicadas emerging from the ground and their shells and it's happening right now. Missouri State Parks say the cicadas will literally "hang precariously from their shells until their wings are fully unfurled and dry, ready to fly." There's been a lot of talk about cicadas this year. After all, this summer has featured the largest emergence of cicadas since 2004. Most of the cicada activity has been taking place from Tennessee to New York, and Missouri has been spared from the billions and billions of cicadas and the shells they leave behind. At least that's what CNN says.