How to Identify a Praying Mantis (and Which Ones Are Native)

For most of the summer, praying mantises are small and easy to miss. By late summer and into fall they are full-grown adults — several inches long, swiveling those triangular heads to watch you, and suddenly turning up on screen doors, fence posts, flower stalks, and porch lights. It is the time of year people notice mantises the most, and the time they are large enough to identify to species. Here is how to recognize one and figure out which mantis you are looking at.

What Makes a Mantis a Mantis

Nothing else in a North American backyard is easily confused with a mantis once you see the whole animal. The telltale features are unmistakable:

• A triangular head that can rotate nearly all the way around — mantises are the only insects that can look over their "shoulder"
• Two large compound eyes set wide on that triangular head, giving the classic alert, staring look
• Front legs folded up in a "praying" posture, lined with spines and built to snap shut on prey
• A long, slender body and, in adults, wings folded down the back; overall green or brown to blend with leaves and stems
• A slow, deliberate, sometimes swaying walk — very different from a fast-scuttling beetle or grasshopper

Mantises are ambush predators that eat other insects, and they are harmless to people — they do not sting, and while a large one can deliver a startling pinch with those spiny forelegs if you handle it roughly, it is not venomous or dangerous. In the garden they are generally considered beneficial, though they are indiscriminate and will eat helpful insects (and occasionally each other) right alongside pests.

The Three You Are Most Likely to Find

Across much of the United States, three species account for nearly every mantis people see — and only one of them is native:

• Chinese mantis (Tenodera sinensis) — introduced; the giant of the group at up to about 4 to 5 inches. Slender, tan to green, usually with a green stripe along the edge of the wings. This is the big mantis most people encounter
• European mantis (Mantis religiosa) — introduced; a bit smaller at around 2 to 3 inches, usually bright green, with a distinctive black-and-white "bullseye" spot on the inside of each front leg
• Carolina mantis (Stagmomantis carolina) — native; smaller still at about 2 to 2.5 inches, mottled gray-green or brown, with short wings that cover only about half the abdomen in females

The two big, common mantises in most yards are the introduced Chinese and European species — often sold as garden "pest control" and long since established in the wild. The native Carolina mantis is smaller and more cryptic, and it can be outcompeted by its larger introduced cousins, which is one reason it is worth learning to recognize the difference.

Reading the Egg Case (Ootheca)

In fall, mantises lay eggs inside a frothy secretion that hardens into a papery, foam-like case called an ootheca — often the easiest way to tell the species apart, and a common find on twigs, stems, and fences through winter. The shape is the giveaway:

• Chinese mantis — a rounded, puffy, cube-ish case about the size of a ping-pong ball, tan and foamy-looking
• Carolina mantis (native) — narrow and elongated, roughly the shape of a slim ridge along the twig
• European mantis — similar to the Carolina case but more uniformly pale in color

A note if you find one indoors: egg cases brought inside on cut branches or firewood can hatch early in the warmth, releasing dozens to hundreds of tiny mantises into your living room. If you find an ootheca on something you are bringing in, leave it outside or set it in a sheltered spot so it hatches on nature’s schedule.

When You Are Not Sure Which One You Have

Color alone will not tell you the species — both green and brown individuals show up within the same kind of mantis — so size, wing length, and that bullseye leg spot matter more than color. Found a mantis on your porch or an odd foamy lump on a twig and want to know which species it is? Take a photo and Spotter will identify the mantis (or its egg case) and tell you whether it is one of the native or introduced species.