What Do Praying Mantises Eat? Insects, Spiders and Even Birds

How do praying mantises catch their prey?

Most mantises are sit-and-wait hunters. A praying mantis perches on a stem, leaf or flower, colored green or brown to match its background, and stays almost perfectly still. Some sway gently from side to side, which may help them look like a leaf moving in the breeze and also helps them judge distance.

When an insect comes close, the mantis turns its head to fix the target in the sharpest part of its eyes. It may creep a little closer, then strike. The front legs shoot forward in a fraction of a second and clamp the prey between rows of sharp spines on the thigh and shin. Few insects can pull free once caught.

A mantis does not use venom and does not bite to kill first. It simply holds the prey and starts eating the part nearest its jaws. Some species have a long foregut that can store food, which helps them make the most of large but irregular meals.

Not every mantis waits in one place. A few ground-living species in dry regions run across open soil to chase prey, and tropical flower mantises look so much like blossoms that pollinating insects fly straight to them.

Which insects do praying mantises eat?

Mantises are generalists: they eat almost any animal they can catch and hold. Prey must move to attract attention, and it must be small enough to grip. As a mantis grows, the size of its prey grows too.

The European praying mantis seems especially fond of grasshoppers and crickets, probably because their jumping and flying movements catch its eye. It also takes:

• Flies, moths and butterflies, often at flowers or near lights
• Bees, wasps and hoverflies, caught while they feed on nectar
• Cockroaches, beetles and bugs that walk within reach
• Spiders, which are common prey for young mantises

Snails, millipedes and earthworms have been recorded occasionally. Mantises are not always put off by prey defenses either. Chinese mantises have been seen eating monarch caterpillars, which carry bitter toxins from milkweed, while discarding the gut contents, possibly to avoid the toxic plant material inside. You can read more about these caterpillars in the monarch butterfly profile.

Do praying mantises eat hummingbirds?

They can, though it is rare. In 2017, a review published in The Wilson Journal of Ornithology collected well over a hundred documented cases of mantises catching small birds from every continent except Antarctica. Most reports came from the United States, and hummingbirds were the most frequent victims, especially the ruby-throated hummingbird.

Mantises catch hummingbirds by waiting on flowers or near sugar-water feeders, the same places where they ambush insects. A hummingbird weighs only a few grams, so a large female mantis can hold one. Many North American reports involve the big Chinese mantis, which can grow to about 11 cm (4.3 in).

Other small vertebrates also turn up on the menu now and then. Large mantises have been recorded catching small frogs, lizards and even small fish from the edge of a pond. These events are remarkable precisely because they are unusual: for nearly all mantises, nearly all of the time, dinner is an insect or a spider.

What do baby praying mantises eat?

A mantis egg case releases dozens to hundreds of tiny nymphs in late spring. They look like miniature adults without wings and start hunting soon after hatching, but their prey must be very small. Typical first meals include aphids, fruit flies, gnats, tiny leafhoppers and other soft-bodied insects.

The first days are the hardest. Many nymphs fail to find food of the right size, and in the European mantis only a small fraction survive the first stage. Brothers and sisters that stay close together often eat each other. Research on Chinese mantises shows that young nymphs also eat pollen, and those that can get it grow faster and survive better, so a mantis’s diet is not quite 100 percent meat.

With each molt the nymph can tackle bigger prey. By midsummer, young European mantises are catching flies and small grasshoppers, and by late summer adults take insects almost as long as themselves.

Do praying mantises eat other mantises?

Yes. Mantises treat other mantises much like any other prey, and a larger mantis will readily eat a smaller one. That is one reason mantises are usually spread out rather than found in groups.

The most famous form of this behavior is sexual cannibalism, when a female eats a male before, during or after mating. It happens most often when females are hungry and need energy to produce eggs. The full story is in why female mantises eat males.

Are praying mantises good for gardens?

Mantises are often described as garden helpers, and they do eat many plant-feeding insects such as grasshoppers, caterpillars and aphids. But they eat useful insects just as readily, including bees, butterflies, hoverflies and other predators. A mantis cannot tell a “pest” from a pollinator.

In temperate regions mantises also produce only one generation a year and do not multiply quickly when a particular insect becomes common. For these reasons, scientists who study biological control consider mantises general predators of little value for controlling any single crop pest. In parts of North America, ecologists are also concerned that the large introduced Chinese mantis may compete with native mantises and other predators.

The bottom line is simple: a praying mantis eats whatever moving creature it can catch and hold, and that is mostly insects and spiders.