Somewhere in a southern European garden, a praying mantis the length of your hand swivels its triangular head, tracks a honeybee with unnervingly human-like eyes, and strikes. It is not supposed to be here. It is a giant Asian mantis, one of two species that scientists have just formally branded invasive across Europe, and it is spreading fast. The story of how it got a foothold is a small, sharp lesson in how a warming world quietly rearranges who lives where, one warm winter at a time.
01 · The newcomersTwo giants from Asia
The insects at the centre of this are Hierodula tenuidentata, the giant Asian mantis, and its relative Hierodula patellifera, the Indochina mantis. Both are natives of Asia, and both are notably larger than Europe’s familiar green native mantis. They have been quietly present in Europe for about a decade, but a 2026 study, drawing on more than 2,300 public sightings, confirmed what naturalists had suspected: their numbers have surged, they are pushing north, and they now meet the formal criteria for invasive species.
02 · The open doorWhy now, after all this time
If they arrived a decade ago, why the sudden surge? The short answer is warmth. These are subtropical insects, and for years European winters were cold enough to keep them in check. As winters mild, that barrier falls away, and territory that was once too cold to survive becomes livable. A warming climate is not a background detail here; it is the mechanism. It is steadily unlocking a whole continent for a predator that simply could not have overwintered there a generation ago.
03 · The city as stepping stoneWarm concrete helps
There is a second, sneakier accomplice: the city. Built-up areas trap heat, staying warmer than the surrounding countryside, a phenomenon called the urban heat island. For a heat-loving mantis, that means towns and cities act as warm refuges, letting the insects stay active and keep hunting later into autumn and winter than they otherwise could. In effect, our own warm concrete is providing a chain of stepping-stone heaters, helping a subtropical predator survive and advance through landscapes that should be too cold for it.
The invaders may be winning partly by weaponising romance. Because the Hierodula females are bigger, they can lure in and devour the native European mantis's males during mating attempts. So the invasion does not just advance by out-eating and out-breeding the locals: it sabotages their love lives, one cannibalised suitor at a time, quietly cutting the natives' ability to reproduce. And the quiet accomplice, again, is your own neighbourhood, whose warm streets let a subtropical hunter overwinter where it never could before.
04 · The numbers gameOut-breeding the locals
Climate opens the door, but sheer fecundity is what floods through it. A single egg case of the giant Asian mantis can hatch around 209 nymphs, nearly double the output of the native European mantis, and with low cannibalism among the young, more of them survive. Stack that reproductive advantage on top of a warming climate and warm cities, and you get exactly what the data show: at one Eastern European site the invader already outnumbered the native mantis by more than seven to one. It is not a fair fight, and the maths favours the newcomers.
05 · What it costsPollinators on the menu
The concern is not the mantis itself but what it eats. Early evidence suggests these giants prey on native insects, including pollinators like honeybees, and even take small vertebrates such as lizards and tree frogs. In a Europe already worried about declining insects, adding a large, hungry, fast-breeding ambush predator is not welcome news. It is worth stressing that this impact evidence is early, the 2026 paper is the first to test it, so “early evidence suggests” is the right register, not “proven.” But the direction of concern is clear, and it is another way the loss of pollinators, like the death of a bee that stings just once, ripples outward.
06 · The payoffSo why are they spreading?
Because a warming climate, warm cities, and prodigious breeding have combined to hand two Asian giants a continent. They survive winters that once stopped them, shelter in the heat of our towns, out-reproduce the locals, and even sabotage the native mantis’s mating. Researchers say the window to contain them has effectively closed, so the task now is to track where they go and understand what they change. It is a small, six-legged illustration of a much larger truth: as the world warms, the map of who lives where is being redrawn, quietly, in gardens and city streets, by creatures simply moving into the space we have opened for them.
Quick questions
Are praying mantises invasive?
Most are not, but two Asian species, Hierodula tenuidentata and H. patellifera, were confirmed as invasive in Europe in a 2026 study. Europe's own native mantis is not invasive. The label applies specifically to these introduced giants.
Why are mantises spreading across Europe?
A warming climate lets these subtropical species survive winters that once killed them, and cities stay warm enough to extend their active season. They also breed faster than natives and are moved around accidentally by humans.
Which giant mantis species are invading Europe?
The giant Asian mantis (Hierodula tenuidentata) and the Indochina mantis (Hierodula patellifera), both native to Asia.
Are giant mantises dangerous?
Dangerous to insects, small lizards, and frogs, yes, but not to people. They have no venom and cannot meaningfully harm a human.
Can mantises hurt humans?
Essentially no. A mantis may pinch or nip if handled roughly, but it is not venomous and the bite causes at most minor irritation.
Do female mantises eat the males?
Sometimes. Sexual cannibalism happens in many species and is more likely when the female is hungry; it can supply nutrients that help her produce more eggs. It is far from guaranteed in every mating.
Why do female mantises eat their mates?
Mainly nutrition. A well-fed female often mates without eating the male, while a hungry one may consume him, boosting her egg output. Hunger, not romance, is the main driver.
How are the Asian mantises harming European wildlife?
Early evidence suggests they eat native insects and pollinators like honeybees, take small vertebrates such as lizards and tree frogs, and can kill native European mantis males during deceptive mating, reducing native reproduction.
Are the invasive mantises replacing the native European mantis?
Evidence points that way. At one Eastern European site the invader outnumbered the native Mantis religiosa by about 7.6 to 1, and they out-breed natives with around 209 nymphs per egg case. This is early evidence, not a settled conclusion.
How did Asian mantises get to Europe?
Most likely accidental human transport, consistent with the plant and ornamental trade, followed by climate-aided spread. The exact original route is not fully confirmed.
Is climate change really behind the mantis spread?
Scientists say warming is a key driver, letting these heat-loving species survive milder European winters and push steadily northward.
Can praying mantises see in 3D?
Yes, uniquely so. They are the only insects known to have true stereoscopic vision, and even use a novel motion-based form of 3D, helping them judge exactly when to strike at prey.
Should I kill an invasive mantis if I find one?
It is better to report sightings to local citizen-science or biodiversity projects than to act on your own. Researchers say the window to contain these species has effectively closed, so tracking their spread now matters most.
Our sources 6 checked
// every claim on this page was checked before it went up