The praying mantis is a fascinating insect often spotted motionless among garden foliage, leading many to wonder if it is feeding on the plants themselves. Praying mantises are not herbivores; they do not consume any plant matter, flowers, or fruit. These insects are strictly predators, known for their unique appearance and their role as voracious hunters. Their survival strategy is focused entirely on capturing and digesting other animals.
Obligate Carnivores: The Praying Mantis Diet
Praying mantises are classified as obligate carnivores, meaning their diet must consist entirely of animal protein to survive. They cannot derive the necessary nutrition from vegetation because their digestive systems lack the enzymes required to process plant material like cellulose. This complete reliance on live prey makes them formidable and indiscriminate hunters.
Their diet is broad and includes any creature small enough to be subdued. Prey ranges from common insects like flies, mosquitoes, and aphids to larger insects such as crickets and grasshoppers. Adult mantises occasionally capture and consume small vertebrates, including lizards, frogs, and, in rare instances, small birds like hummingbirds. They will eat whatever is moving and within their reach, even preying on other mantises.
Nymphs, or young mantises, start with smaller prey like fruit flies, gradually shifting to larger insects as they grow. The mantis requires a consistent intake of live animal matter to support its rapid growth and high-energy hunting lifestyle. Attempts to feed them dead insects or plant-based foods typically fail, as their feeding response is often triggered by movement.
Hunting Strategy and Specialized Anatomy
The mantis is primarily an ambush predator, employing a sit-and-wait strategy to capture its meals. It remains perfectly still, blending into its surroundings using camouflage, and waits for unsuspecting prey to wander nearby. This predatory technique is aided by their unique anatomy, particularly their triangular head.
The triangular head can rotate more than 180 degrees, a rare trait among insects, allowing the mantis to scan its environment for potential prey without moving its body. Exceptional eyesight and depth perception enable the mantis to accurately calculate the distance to its target. Once prey is within range, the mantis strikes with lightning speed using its specialized raptorial forelegs.
These forelegs are highly adapted for seizing and holding prey. The femur and tibia are lined with rows of sharp, overlapping spines that act like a jackknife when they snap shut. This rapid strike instantly pins the prey and holds it securely while the mantis begins to feed.
Why the Confusion About Plants?
The common misunderstanding that praying mantises eat plants stems from the fact that they are almost always seen on vegetation. Plants serve as their primary habitat, providing excellent camouflage and strategic hunting grounds. A mantis will often perfectly mimic a stick, a leaf, or a flower petal to ambush the insects attracted to the plant.
Flowering plants attract a high density of nectar-seeking insects, which become a readily available food source. Furthermore, mantises rely on plants for reproductive purposes, using stems and leaves as sites to lay their egg cases, known as oothecae. Their presence in gardens is beneficial, as they function as natural pest control by eating harmful insects like caterpillars and aphids.