Praying mantises are voracious predators, eating a wide variety of insects and even small vertebrates. Their diet usually consists of crickets, grasshoppers, butterflies, moths, and flies. However, some larger mantis species have been known to prey on lizards, frogs, snakes, birds, and even rodents!
Typical Prey Size
Most praying mantis species eat prey that is roughly one third their own body size or smaller. For example, a typical European mantis (Mantis religiosa) reaches 2-3 inches (5-7 cm) long as an adult. It will readily consume insects up to about 1 inch (2.5 cm) in length. Smaller mantis species, like the ghost mantis and flower mantis, may only be 0.5-1 inch (1.5-2.5 cm) in size. They usually eat tiny insects like fruit flies, aphids, and other diminutive bugs.
However, giant species of praying mantis can grow much larger, reaching 4-6 inches (10-15 cm) or more. Larger mantis species have a greater appetite and can tackle more substantial prey.
Larger Prey
Some of the largest mantis species like the giant Asian mantis (Hierodula membranacea) and giant African mantis (Sphodromantis lineaola) have been documented catching and eating:
- Lizards – including smaller skinks, anoles, and geckos
- Small frogs and toads
- Nestling birds – especially hummingbirds, sparrows, wrens
- Rodents – young mice, voles, shrews
- Snakes – small, thin snakes like garter snakes can be overpowered
- Fish – mostly smaller species that can be snatched from the water’s edge
There is even one account of a large Chinese mantis consuming a small bat in captivity when both were contained in an insect habitat at a zoo. While unusual, the mantis was able to grab the bat and eat it head first over the course of several hours.
Size Limitations
Prey size is limited by the grasping forelegs and mouthparts of the mantis. Their raptorial front legs are designed to clasp and hold prey tightly in a Vice-like grip. The legs are tipped with an array of sharp spines that can further pin prey in place. Meanwhile, chewing mouthparts are used to methodically eat the victim alive.
However, very large or heavy prey can overwhelm a mantis’ grasping capacity. Additionally, their chewing mouthparts have a limited gape size and can’t easily break through tougher vertebrate scales, feathers, fur, or hide.
As a general rule, prey items more than 50% the mantis’ own body mass would be difficult and hazardous for them to tackle. Eating prey that is too large risks injury to the mantis. And the mantis needs to be able to physically maneuver and position such large prey in order to consume it.
Largest Documented Prey
The largest verified prey eaten by a praying mantis are:
- Lizard – a giant Asian mantis was observed catching, killing, and consuming a 4 inch (10 cm) long lizard in Hawaii in the late 1800s. The lizard represented over 60% of the mantis’ own body mass.
- Hummingbird – a South American giant montis was documented eating a 3 inch (8 cm) long hummingbird after ambushing it at a flower feeder. The hummingbird was nearly 50% the mantis’ own mass.
- Rodent – a heavy-bodied Giant African mantis eaten a newborn mouse that was about 35% its own body weight in captivity in Europe in the 1950s.
In these cases, the enormous prey items require the mantis to exert its strength to the limit to subdue, manipulate, and consume the victim. Eating takes many hours to complete. And the mantis is left extremely full and lethargic afterwards.
Exceptional Cases
There are a few extraordinary stories of praying mantises preying on even larger animals, including:
- Fish – accounts of giant mantises catching small fish up to 4 inches (10 cm) long near the water’s edge. The fish represented over 70% of the mantis’ weight.
- Bird – an unverified story exists of a giant montis from Southeast Asia eating a 6 inch (15 cm) long finch. However, details are scarce.
- Mammal – isolated and unsubstantiated tales describe giant mantises eating very small mammals like shrews and bats close to their own body weight.
However, these cases either lack documentation or push the limits of what mantises are physically capable of. Most experts are skeptical of such extreme predation events.
Conclusion
To summarize the biggest prey a praying mantis can eat:
| Typical Prey Size | Up to 1/3 mantis’ length |
| Larger Prey Reported | Lizards, hummingbirds up to ~50% mantis’ weight |
| Largest Verified | Lizard ~60% mantis’ weight |
| Extreme Claims | Fish, birds up to 70-100% mantis’ weight |
Most mantis species eat insects smaller than themselves. But giant mantises can prey on small vertebrates, with lizards and hummingbirds being the largest verified prey. Claims of them eating animals larger than themselves lack solid proof. Ultimately, the grasping arms and chewing mouthparts place practical limits on just how big their dinner can be!
