
Iowa’s Silent Assassin: a Cannibal that Eats Bugs, Birds, & Lizards!
Across the quiet, wind-swept fields of Iowa, a tiny predator lurks with stealth and deadly precision. The praying mantis, often unnoticed by the casual observer, is one of nature’s most efficient and fascinating hunters. With its iconic “prayer-like” posture and razor-sharp reflexes, this insect is far more than meets the eye. From insects and spiders to small birds and lizards, these silent assassins don’t discriminate when it comes to mealtime, even occasional munching on other mantid.
A Chinese Praying Mantis found at my campsite, Labor Day 2024.
Meet Iowa’s Praying Mantises
While praying mantises are found throughout much of the United States, Iowa is home to 3 known species, each bringing its own set of skills to the state's ecosystems. The two most common species in Iowa are the Chinese mantis (Tenodera sinensis) and the European mantis (Mantis religiosa), both of which are actually non-native species that have established themselves here.

Chinese Mantis (Tenodera sinensis): Originally introduced accidently to the U.S. as a form of pest control, this is the largest species of mantis in Iowa, sometimes reaching over four inches in length. The Chinese mantis is a formidable predator with long, powerful forelegs perfect for snatching up unsuspecting prey. Its color ranges from brown to bright green, allowing it to blend seamlessly into grasslands and shrubbery. These are the ones you may find stalking your hummingbirds, frogs, and lizards.
European Mantis (Mantis religiosa): Slightly smaller than its Chinese cousin, this species has an equally intimidating appetite. The European mantis is recognized by a distinctive green or brown coloring and a small black "eye spot" on the inside of its front legs. Like the Chinese mantis, it was introduced to the U.S. to help control pest populations.
Although these non-native mantids dominate the scene, Iowa is also home to a smaller, native species: the Carolina mantis (Stagmomantis carolina). This diminutive assassin, which rarely grows beyond two inches, is often camouflaged in shades of green, brown, or gray to match its habitat. While it’s smaller, the Carolina mantis is no less fierce than its larger counterparts when it comes to hunting down insects and small critters.
A Diverse Diet: Bugs, Birds, & Lizards
One of the most striking features of praying mantis is their varied diet. While the bulk of their meals consists of smaller insects like grasshoppers, crickets, and beetles, these predators are known to tackle much larger prey. When the opportunity arises, a praying mantis won’t shy away from making a meal out of small vertebrates like birds, frogs, and even lizards! Even if they were originally trying to make a meal out of the mantis, like this poor fellow below.
You might be surprised to learn that there are documented cases of mantises catching and eating hummingbirds (video below)! Thanks to their incredible patience and lightning-fast reflexes, they can ambush these tiny birds while they’re sipping nectar from flowers. While this isn’t their everyday meal, it highlights just how versatile and opportunistic these insects can be.
The praying mantis is known for their impressive hunting techniques. They have two bulging, compound eyes that give them 3D vision, allowing them to accurately judge the distance to their prey. Additionally, their triangular-shaped heads can swivel up to 180 degrees, giving them a panoramic view of their surroundings—an essential tool for tracking moving targets. And their jaws; strong enough to easily break even the toughest skin.
Once they lock in on a target, they strike with lightning speed, using their raptorial forelegs to snatch prey and hold it tight. Spiny ridges on these legs ensure that escape is nearly impossible. The mantis will then start eating its prey alive, typically starting with the head and brain.
Mating and the Notorious Cannibalism
Praying mantises have another claim to fame—sexual cannibalism. It’s a well-known (and slightly terrifying) fact that female mantises sometimes (often) eat their mates during or after mating. While this doesn’t happen in every instance, it’s common enough to have earned mantises a rather notorious reputation. The act may increase the chances of successful reproduction, providing the female with a nutrient boost that benefits her offspring.
While the praying mantis may be intimidating, it plays a critical role in Iowa’s ecosystems. These voracious hunters help control the population of various insects, many of which are considered pests. By keeping the numbers of destructive insects like grasshoppers, caterpillars, and beetles in check, mantids contribute to the health of crops and gardens across our great state of Iowa.
Their unique behavior, impressive hunting skills, and otherworldly appearance make them one of the most interesting creatures in Iowa’s ecosystem. So, the next time you spot one of these silent assassins perched on a leaf or branch, take a moment to appreciate its deadly beauty.
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