The praying mantis (order Mantodea) is a specialized, strict carnivore and an apex hunter within the arthropod world. Its distinctive upright posture, with folded forelimbs, is a poised stance for seizing its next meal, not one of reverence. The mantis diet is a highly efficient, opportunistic feeding strategy prioritizing survival.
The Essential Arthropod Diet
The core diet of a praying mantis consists almost entirely of other arthropods. As a generalist insectivore, it feeds based on availability and size, subduing any invertebrate it can. This includes common garden and field insects, such as house flies, crickets, grasshoppers, moths, and various species of beetles.
The mantis also consumes smaller, soft-bodied insects like aphids, caterpillars, and leafhoppers. Spiders are a regular part of the diet. Hunting success is determined by the mantis’s body size, as it must be large enough to restrain and consume its victim. This opportunistic reliance means beneficial insects, like bees and butterflies, are caught just as often as common pests.
Mastering the Ambush: Hunting Techniques
Prey acquisition is an ambush strategy relying on patience and superb camouflage. The mantis uses cryptic coloration to blend seamlessly with its environment, often swaying to mimic vegetation movement. When a victim comes within striking distance, the mantis uses its highly mobile, triangular head and large compound eyes to calculate the distance. The mantis is the only known insect that can rotate its head a full 180 degrees, allowing it to survey its surroundings without moving its body.
The capture is incredibly fast, often taking only 50 to 70 milliseconds. This speed is achieved through the explosive extension of the raptorial forelegs, which are specialized, spiked appendages. These forelegs are lined with sharp, interlocking spines that snap shut, pinning the prey in a secure grip. After the strike, the mantis pulls the immobilized prey toward its mouthparts to begin consumption, often starting with the head.
When Prey Gets Bigger: Dietary Shifts and Unusual Meals
A mantis’s diet changes significantly as it progresses through its life stages. Newly hatched nymphs feed on very small, soft-bodied prey like fruit flies, gnats, and aphids. As they undergo successive molts and increase in size, their diet expands to include progressively larger insects. This expansion is limited only by the mantis’s physical capacity to capture and hold the animal.
The most notable variations in diet involve cannibalism and the consumption of small vertebrates. Cannibalism is common, especially among siblings when food is scarce, and is often observed during mating. The female sometimes consumes the male, often beheading him, during or immediately after copulation. This act is thought to be an adaptive foraging strategy, providing the female with a protein-rich meal that increases the number and quality of eggs she produces.
On rare occasions, the largest species of mantises prey on small vertebrates. Documented instances include the capture and consumption of small frogs, lizards, mice, and even small birds like hummingbirds. These unusual meals are typically only possible for larger tropical species. They occur when the vertebrate ventures too close to the mantis’s striking range.