Mantodea or mantises is an order of insects which contains approximately 2,000 species in 9 families worldwide in temperate and tropical habitats. Most of the species are in the family Mantidae. Historically, the term “mantid” was used to refer to any member of the order because for most of the past century, only one family was recognized within the order; technically, however, the term only refers to this one family, meaning the species in the other eight recently-established families are not mantids, by definition (i.e., they are empusids, or hymenopodids, etc.), and the term “mantises” should be used when referring to the entire order. A colloquial name for the order is “praying mantises”, because of the typical “prayer-like” stance. The term is often mis-spelled as “preying mantis”, and this an eggcorn since mantises are notoriously predatory. The word mantis is Greek for “prophet” or “fortune teller”. In Europe, the name “praying mantis” refers to only a single species, Mantis religiosa. The closest relatives of mantises are the orders Isoptera (termites) and Blattodea (cockroaches), and these three groups together are sometimes ranked as an order rather than a superorder.
About 20 species are native to the United States, including the common Carolina mantis, and only one in Canada. Two species (the Chinese mantis and the European Mantis) were deliberately introduced to serve as pest control for agriculture, and have spread widely in both countries. While it is legal to keep native mantises as pets or to sell egg cases for gardening, non-native species are illegal to possess and release in the United States, under the Non Native Invasive Species Act of 1992.(wiki)