Who Was Knocking?

The birdbath needed filling, and I reached to open the porch door to get the watering can and almost set my hand on this huge (five inches?) green creature, Mantis religiosa, or the "praying Mantis" ("mantis" meaning "prophet") clinging to the door and screen. This startling all-green mantis--its coattails resembling folded leaves, as artfully dressed as a geisha--is most likely non-native, a European mantis, the kind kept as a pet. I'm not kidding; it says all over the Internet that praying mantises make "marvelous" pets, I suppose if you don't step on them or suck them up in the vacuum cleaner.

In the autumn, after a summer of growing to adulthood, mantises mate, and the male of the species is puny, skinny, and brown, so I'm guessing this big bold one is an adult female and she's about to mate or has recently done so. The females perform "sexual cannibalism," a spectacle I don't care to see. This is the first time I've looked a mantis in the face. What was she doing at my door today? Did she think there might be males in the house? I left her, returned five minutes later, and she was gone. Could she have had a message for me? What was it? "Be big, green, lean, mean, and beautiful?"