What Does the Praying Mantis Do in a Garden? The Truth About Nature's Fiercest Garden Guardian
Here’s a question that divides gardeners and entomologists alike: is that alien-looking insect with its prayer-like posture a hero that saves your tomatoes from destruction, or a villain that devours the very pollinators you've worked so hard to attract? The answer reveals one of the most complex and misunderstood relationships in the gardening world. The praying mantis is simultaneously a ruthless predator of garden pests and an indiscriminate killer of beneficial insects, making its overall impact on your garden far more nuanced than most people realize .
For decades, gardeners have celebrated mantises as beneficial insects, purchasing their egg cases from catalogs and releasing them with hope and anticipation. And indeed, these ancient predators do consume enormous numbers of insects that would otherwise damage your plants. But research from university extension services across the country paints a more complex picture: mantises eat everything they can catch, including the bees and butterflies that pollinate your flowers and vegetables . Understanding what mantises actually do in gardens—the good, the bad, and the fascinating—helps you make informed decisions about whether to encourage them and how to balance their presence with other garden goals. For those committed to supporting healthy garden ecosystems, resources like free sample packs can help you establish the diverse insect populations that maintain ecological balance.
The Good: Mantises as Natural Pest Controllers
Let's start with why mantises have earned their reputation as garden allies. These insects are carnivorous predators that consume a wide variety of common garden pests .
What Garden Pests Do Mantises Eat?
Praying mantises are opportunistic hunters that will eat virtually any insect they can catch . Their menu includes many insects that gardeners consider pests :
- Aphids: Those tiny sap-suckers that cluster on rose buds and vegetable stems
- Caterpillars: The larvae of moths and butterflies that chew holes in leaves
- Grasshoppers: Voracious leaf-eaters that can decimate plants
- Flies: Both nuisance flies and those that damage plants
- Mosquitoes: Disease vectors that breed in garden water features
- Moths: Adults whose caterpillars damage plants
- Scale insects: Hard-to-control pests that attach to stems and leaves
- Leafhoppers: Jumping insects that suck plant juices
- Beetles: Many species that damage garden plants
This appetite for pests makes mantises appealing to organic gardeners seeking alternatives to chemical pesticides . As one gardening expert notes, mantises "feed on many harmful insects, including grasshoppers, moths, caterpillars, and beetles, reducing the need for chemical pesticides" .
The Hunting Strategy
What makes mantises effective is their hunting technique. They are ambush predators that remain motionless for hours, camouflaged against vegetation, waiting for prey to wander within striking range . When an unsuspecting insect comes close, the mantis strikes with blinding speed—taking just 50-70 milliseconds to capture its prey .
Their physical adaptations make them formidable hunters :
- Raptorial forelegs: Lined with sharp spines that interlock to create an inescapable cage
- Triangular head: Can rotate 180 degrees to see in all directions
- Excellent vision: Compound eyes provide exceptional depth perception for judging strike distances
- Camouflage: Coloration that matches leaves, stems, or flowers makes them nearly invisible
This combination of patience, speed, and precision means that mantises can be effective predators of garden pests .
No Damage to Plants
Unlike many insects that gardeners battle, mantises cause absolutely no damage to plants . They don't eat leaves, suck sap, or burrow into stems or fruits. As one extension service notes, mantises "don't eat our plants" . Their only interest in vegetation is as a hunting platform and camouflage.
The Bad: Mantises Eat Beneficial Insects Too
Here's where the mantis's reputation becomes complicated. Mantises are not discriminating predators—they eat whatever they can catch, regardless of whether humans consider it a pest or a helper .
Pollinators on the Menu
Gardeners who work hard to attract bees, butterflies, and other pollinators may be dismayed to learn that mantises regularly eat them . The list of beneficial insects mantises consume includes:
- Honeybees and native bees: Essential pollinators for many crops and flowers
- Butterflies: Both pollinators and aesthetic garden favorites
- Ladybugs (ladybirds): Themselves voracious predators of aphids
- Lacewings: Beneficial insects whose larvae eat aphids
- Hover flies (syrphids): Pollinators whose larvae also eat aphids
- Other mantises: Cannibalism is common, especially when food is scarce
As one university extension service bluntly states, mantises "do not discriminate between beneficial and harmful insects and will eat their siblings, other beneficial insects, butterflies and pollinators such as bees" .
Quantifying the Impact
So how significant is this predation on beneficial insects? Research suggests that while mantises do eat pollinators, their overall impact may be limited by their relatively low feeding frequency . According to the University of California Integrated Pest Management program, "mantids are relatively inactive, and despite their large size, each individual consumes relatively few insects" .
This means that a single mantis in your garden won't decimate your pollinator population. However, if mantises become very numerous, or if you have a small garden with limited pollinators, their impact could be more noticeable .
The Hummingbird Factor
Perhaps the most shocking item on the mantis menu is hummingbirds . Multiple documented cases exist of mantises capturing and consuming these tiny birds, typically at feeders or flowers where hummingbirds feed .
Here's what happens:
- Mantises ambush hummingbirds at feeders or flowers, striking when the bird lands
- The mantis grips the bird's head or neck with its spiny front legs
- The bird is typically unable to escape due to the mantis's grip and spines
- The mantis begins eating, often starting with the head
While disturbing to bird lovers, these incidents are relatively rare and typically involve larger mantis species like the Chinese mantis preying on smaller hummingbird species . Twelve mantis species are known for capturing birds, with ruby-throated hummingbirds being prime targets because of their small size .
If you maintain hummingbird feeders, positioning them away from dense vegetation where mantises lurk can reduce risk .
The Verdict: Friend, Foe, or Something In Between?
Given these conflicting roles, what's the final word on mantises in gardens? The consensus from entomologists and extension services is surprisingly nuanced.
"Negligible" Overall Impact
Iowa State University Extension concludes that mantises' "overall impact in the garden and landscape is probably negligible (though they are fun to watch!)" . This assessment reflects the reality that while mantises do eat pests, they also eat beneficials, and their relatively low feeding rate means they don't dramatically shift pest populations either way.
Not Reliable Pest Control
An Ask Extension expert put it even more directly: "Adding praying mantises to a garden can be a lot of fun and some insects will certainly be eaten, but they are not considered a reliable control measure for garden insects. They eat too many different kinds of things (including siblings!) and in too small quantities to be effective pest control" .
For specific pest problems, the expert recommends "specialist predators" like minute pirate bugs for thrips, which are more targeted and effective .
Mostly Neutral with Benefits
Other experts describe mantises as "mostly neutral" in their garden impact . Birding experts Kenn and Kimberly Kaufman note that mantises are "just as likely to eat pollinators as pests, so their impacts are mostly neutral" .
This doesn't mean mantises have no place in gardens. It means their value is more as fascinating garden inhabitants than as reliable pest control agents .
A Sign of a Healthy Ecosystem
One thing experts agree on: the presence of mantises indicates a healthy garden ecosystem . Illinois Extension notes that "Praying Mantis may be stalking prey in our gardens and startling our young but they are a good sign of a healthy ecosystem" .
Mantises require abundant insect prey to survive, so their presence tells you that your garden supports a diverse insect population. This diversity, including both pests and beneficials, is actually a sign of ecological health .
The Mantis Life Cycle in Your Garden
Understanding the mantis life cycle helps you appreciate their seasonal presence in your garden .
Spring: Hatching
Mantises overwinter as eggs inside protective structures called oothecae—foam-like cases attached to branches, stems, or fences . In spring, typically April through May depending on your location, tiny nymphs emerge . These nymphs are miniature versions of adults, just a few millimeters long .
At this stage, they immediately begin hunting tiny insects like aphids, thrips, and fruit flies . They also begin eating each other—sibling cannibalism is common when food is scarce .
Summer: Growth and Hunting
Throughout summer, mantis nymphs grow through a series of molts, shedding their exoskeletons to accommodate their increasing size . Each molt leaves behind a perfect insect-shaped shell, often found still clinging to vegetation .
As they grow, they take larger prey—moving from aphids to flies, then to crickets, grasshoppers, and moths . By late summer, they reach full size and, in winged species, develop functional wings .
Fall: Mating and Egg-Laying
In late summer and fall, adult mantises mate. This is when sexual cannibalism may occur, with females sometimes eating males during or after mating . The female then produces one or more oothecae, attaching them to branches, stems, fences, or buildings .
The ootheca hardens into a protective case that will insulate the eggs through winter . The adult mantises die with the first hard frost, their life's work complete .
Winter: Dormancy
Throughout winter, the eggs remain in diapause inside their protective case, waiting for spring warmth to trigger hatching . This cycle repeats annually, with exactly one generation per year in temperate regions .
How to Attract Mantises to Your Garden
If you decide you want mantises in your garden despite their mixed impact, here's how to encourage them .
Plant Diverse Vegetation
The best way to attract mantises is to "fill your space with a wide range of plants" . Native plants work best because they "more readily attract tasty insects"—the prey mantises eat . Diverse plantings provide:
- Hunting grounds with varied structure
- Camouflage options for different mantis species
- Attraction for insect prey
- Shelter from weather and predators
- Ootheca attachment sites
Avoid Insecticides
This is critical. Pesticides kill mantises directly and eliminate their food supply . If you want mantises in your garden, you must avoid chemical insecticides entirely .
Provide Water Sources
Mantises drink water droplets from leaves and surfaces. Regular garden watering or misting provides the moisture they need .
Leave Perennial Stems Through Winter
Many gardeners "hold off to cut back perennials and grasses until spring when the new crop has hatched" . This preserves oothecae attached to stems and provides overwintering habitat .
Purchasing and Releasing Mantis Egg Cases
Many gardeners purchase mantis egg cases from garden catalogs and online suppliers. If you choose to do this, follow these guidelines .
Where to Find Oothecae
Praying mantis egg cases are "often available from mail order garden and seed supply companies" . You can also sometimes find them in garden centers in spring .
Proper Storage
If you purchase or find an ootheca in winter, store it properly until spring:
- Keep it in a box or jar in an unheated garage, porch, or shed
- Maintain temperatures above freezing but below 50°F
- Do NOT bring it indoors—warm temperatures trigger premature hatching
Bringing an ootheca indoors can result in "two hundred tiny mantids suddenly start pouring out of the egg case" in January or February, when no food is available and release is impossible . As one extension agent drily notes, "At that point, a vacuum cleaner has been found to be the most efficient way to de-mantid the room" .
Spring Emergence
Bring the ootheca indoors in mid-spring (typically mid-May for northern regions) and watch for hatching . When nymphs emerge, you have a short window to release them before they begin eating each other .
As Iowa State University Extension advises, "They will be all right together for a day or two but then they will begin to eat each other. To maximize the number of survivors, nymphs need to be moved to separate cages, or more practically, scattered around the outdoor environment after a day of entertaining observation" .
Raising Nymphs Is Difficult
For those hoping to raise mantises through to adulthood, be warned: "Raising nymphs through to adult stage in captivity is incredibly difficult" . Most will die from starvation, cannibalism, or failed molts . By the end of summer, "usually only one adult is left" from an entire ootheca .
Native vs. Introduced Mantis Species
An important consideration for gardeners is whether the mantises in their garden are native or introduced species .
Introduced Species Concerns
In North America, most large mantises belong to introduced species from Europe and Asia . These include the Chinese mantis (Tenodera sinensis) and European mantis (Mantis religiosa) .
These introduced species "can cause problems when their populations are unnaturally high" . They are more likely to "catch many bees, butterflies and other pollinators, and they have even been known to kill hummingbirds on occasion" . They may also be displacing native mantis species like the Carolina mantis (Stagmomantis carolina) .
Managing Overpopulations
If your garden seems overrun with mantises, experts suggest you "can pick some off by hand (wear gloves) and remove them" . In late fall, you can also "look for the distinctive mantis egg cases on your plants and destroy those to reduce the next year's population" .
Practical Tips for Coexisting with Mantises
Whether you love them or worry about them, here's how to manage mantises in your garden .
If You Have Hummingbird Feeders
Position feeders away from dense vegetation where mantises lurk . Check feeders regularly for mantises lying in ambush. If you find a mantis on or near a feeder, relocate it carefully to another part of the garden .
If You're Concerned About Pollinators
Remember that mantises eat relatively few insects overall . Their impact on pollinator populations is usually minimal unless mantis numbers are very high or your garden is very small .
If You Find an Ootheca
Decide whether to leave it, move it, or destroy it based on your goals . If you want more mantises, leave it in place or move it to a protected garden spot . If you're concerned about mantis overpopulation, destroy it .
If You're Handling Mantises
Remember that mantises can deliver a painful pinch or bite if threatened . The best way to move a mantis is "with something other than your hand" . Use a stick or leaf to gently guide them .
Conclusion: Appreciating Mantises for What They Are
So, what does the praying mantis do in a garden? The answer is complex and beautifully nuanced. Mantises eat pests—aphids, caterpillars, grasshoppers, and flies that damage your plants . They also eat beneficials—bees, butterflies, and even each other . Their overall impact on pest populations is probably negligible, and they're not reliable for pest control . But their presence indicates a healthy, diverse ecosystem with abundant insect life .
Perhaps the best way to think about mantises in gardens is as fascinating inhabitants rather than as tools. They are creatures of beauty and wonder—ancient predators that have patrolled vegetation for 400 million years . Their alien appearance, their patient hunting style, their dramatic life cycle—these are gifts to gardeners who take time to observe.
The mantis doesn't save your tomatoes single-handedly. It doesn't destroy your pollinator population either. It simply lives its ancient life in your garden, catching what it can, growing through its molts, mating, and leaving behind oothecae for next year. In doing so, it adds a layer of complexity and fascination to the ecosystem you tend.
As one gardener put it after researching mantises: "So, great: have a new friend in the garden that I will be visiting periodically!" . That may be the perfect attitude—appreciation for what mantises are, without unrealistic expectations about what they do.
The praying mantis in your garden is not a hero or a villain. It's simply a predator, doing what predators have done for hundreds of millions of years. And that, in itself, is remarkable enough.