Good thing you put it back. My mom tells a story of one that was left on a windowsill in the sun and she had to scrape up hundreds of tiny geen mantises with a post card when they hatched. Nature bug that she is, she rescued every one and put them in the garden.
I'm with imzadi, looks very creepy to me, like outta some really bad horror movie ... If my thumbs weren't so green, I'd be the worst gardener in the world, bugs and bug-related "products" scare me silly. Whoever invented rubber handed gardening gloves has my profound thanks.