Keeping Mantises

Before you start

Foreign mantises can't be brought into Korea

Under Korea's Plant Protection Act, most live foreign insects are treated as pests and banned from import. Only species cleared by a risk assessment are exempt, and we found no source showing any foreign mantis on that list. Don't buy species like the orchid mantis you see in overseas videos through direct overseas purchase or second-hand sellers.

Inside national, provincial, and county parks you need a permit to collect insects. Bring home a common native mantis from a neighborhood field or park instead.
Mantises eat only live, moving prey. First make sure you can keep getting feeder insects.
Most of Korea's large mantises don't live past one year. It's normal for them to die in late autumn.

Checklist before bringing one home

I'm bringing home a native mantis from my neighborhood to observe (not a foreign species)The enclosure is at least 3 times as tall as the mantis is longThere's mesh or cloth on the ceiling to hang fromThere are holes for air flowOnly one mantis per enclosureI can get live prey that matches its body sizeI won't touch it while it molts, and I'll remove leftover preyI plan to release it where I found it when I'm done observing

Enclosure

Size: height matters more than floor space

When molting, a mantis hangs upside down from the ceiling and slides its body downward out of the old skin. If the enclosure isn't tall enough, the molt fails. A common rule is height at least 3 times body length, width at least 2 times. Sources differ, though: Korean sources say 2–3 times, while the UK's Amateur Entomologists' Society (AES) recommends at least 4 times from the tip of the branch to the floor. It's safer to go bigger.

Body length	Height (3×)	Width (2×)	Example
1–2 cm (newly hatched nymph)	6 cm or more	4 cm or more	Plastic cup with a vented lid
4cm	12 cm or more	8 cm or more	Small bug box
8–10 cm (adult Chinese mantis)	24–30 cm or more	16–20 cm or more	Upright terrarium

Ceiling and walls

Make the ceiling something claws can grip, like mesh or cloth. A glass or smooth plastic ceiling gives them nothing to hold.
Add a branch at an angle for climbing and hanging.
Stale air can lead to mold and molting problems, so put vents in the lid or sides.

Temperature, humidity, and water

Temperature: Korean sources say native Korean mantises don't need extra heat at normal indoor summer temperatures. Overseas care guides for the Chinese mantis suggest 20–26°C. In warmer conditions they grow faster and may live shorter lives.
Humidity: Some care guides recommend 60–65% for the Chinese mantis and 60–70% for the giant Asian mantis. Too dry and molts fail; too damp and mold grows.
Water: Instead of a water dish, lightly mist the enclosure walls and the mantis will drink the droplets. Small nymphs can drown in drops, so don't let large drops pool. Misting once a day or less is enough.

Care by stage

① When you find an egg case

If you can, leave the egg case where it is outdoors and observe it there. If you bring it into a warm room in midwinter, dozens to hundreds of young will hatch before spring, when there's nothing to feed them.

Some keepers give egg cases of temperate mantises a cold period. Overseas sources say 8 weeks or more at 12–15°C; Korean sources mention keeping them outside somewhere cold and dark, or in the fridge. Temperatures and durations vary from keeper to keeper, and there's no set answer.

② When the young hatch

Fix the egg case near the top of the enclosure, facing the same way it was originally attached. The young come out of the egg case and molt for the first time while hanging from silk threads, so leave at least 5–10 cm of empty space below it.
If you use double-sided tape, the young can stick to the exposed glue and die. Cover every sticky surface.
One Chinese mantis egg case produces roughly 100–300 young. Siblings eat each other too, so keep only the few you'll raise and release the rest near where you found the egg case.

③ Young nymphs (1st–3rd instar)

With plenty of hiding places and food you can keep them together for a short time, but by the 2nd or 3rd molt at the latest, raise them one per container.
Many keepers raise them one each in plastic cups with vented lids.
Feed them often so their abdomens don't get skinny.

④ Older nymphs (4th instar on)

As they grow, switch to an enclosure that fits their body length.
The time between molts gets longer. Before the final molt the wing buds swell noticeably.

⑤ Adults

Once they have wings they don't molt anymore. After becoming adults they can't regrow lost legs.
Males usually die before females.

Feeding chart

Stage	Food	Notes
1st instar	Fruit flies (a short-winged, flightless strain)	Small fruit flies (D. melanogaster, about 1.6 mm) work well. Larger D. hydei (about 3 mm) are fine for young of big mantises but too big for small species. They also eat aphids.
2nd instar	Fruit flies, small insects	—
3rd instar	Large fruit flies (D. hydei), small crickets	—
4th instar on · Adult	House flies and blow flies, crickets, feeder roaches, grasshoppers	Increase the size as the mantis grows. Never give stinging insects such as bees or wasps.

Prey size: Some care guides say "no more than 1/3 of body length," while others say "adults will eat prey as big as themselves." Start small, see how well it catches, and go up from there.
How often: There's no official standard. Some care guides recommend every 1–2 days for nymphs, and about every 3 days for older nymphs and adults. If the abdomen is plump, it's fine to skip.
Remove leftover crickets or grasshoppers. They can chew on a molting mantis and hurt it.

Molting

Failed molts are considered the most common cause of death in captive mantises.

How many molts?

It depends on species, individual, and conditions. One care source says Korean mantises molt 7 times on average, another says the Chinese mantis molts about 6 times for males and about 7 for females, and another says 8 for the giant Asian mantis. In lab studies, males of the same species became adults at the 6th instar in some cases and the 7th in others. "Males molt one fewer time" is only a tendency, not a rule. A Japanese study found 5–7 molts for the red long-necked giant mantis.

Signs a molt is coming

For a few days beforehand it refuses food and moves sluggishly.
It hangs upside down from the ceiling and stays still.
Before the final molt, the wing buds are visibly swollen.

Why molts fail

Enclosure not tall enough
Too dry or too damp
Nothing to grip on the ceiling, so it falls
Opening, moving, or touching the enclosure during the molt
Leftover feeder insects getting in the way
Poor air flow

After molting

Keepers usually hold off on food for about a day until the body hardens.
Bent legs or wings in a nymph sometimes straighten out at the next molt. Bent wings on an adult won't get better.

Mating and lifespan

Mating: Feed both the male and the female well first, then place the male behind the female while she is eating. Separate them as soon as they finish. For research on males being eaten during mating, see the hunting story.
Egg cases: A female can lay egg cases without a male, but unfertilized eggs won't hatch.
Lifespan: Korean care sources say about 7–8 months on average from hatching, and that females kept indoors sometimes live until January–March of the next year. Overseas sources give 8–12 months for the Chinese mantis and 6–12 months for the giant Asian mantis.

FAQ

It won't eat.

When a molt is near, a mantis stops eating for a few days and hangs still and upside down from the ceiling. Don't add food then; just wait.

If the abdomen is plump, it may already be full. It also won't eat prey that is too big or doesn't move. Females around egg-laying time and old individuals in late autumn eat less, too.

It fell to the floor while molting.

Don't pull the old skin off. Mist the enclosure walls (not the mantis) to raise the humidity, and hold a grippable surface such as a paper towel or mesh low so it can hang head down. Then leave it alone until it hardens (from keepers' sources).

Before the next molt, check the enclosure height and ceiling material again.

It has black spots on its body.

Keepers often see these as scars from rubbing against the enclosure walls, a failed molt, or poor nutrition, and say they're usually not life-threatening.

If it turns black, stops eating, and becomes weak, it may be an infection, so keep it apart from others. We found no reliable source on how to diagnose or treat insect diseases.

Can I keep two in one enclosure?

Not recommended. Mantises eat other mantises, even when you keep feeding them. By the 2nd or 3rd molt at the latest, raise them one per container.

Do mantises bite people?

When threatened, they occasionally bite or pinch with their leg spines. They have no venom and usually can't break the skin, so it just stings a little. Wash the spot with soap and water, and see a doctor if swelling spreads or you get a fever.

How do I mate them safely?

Feed both the male and the female well for a few days beforehand. Keepers have observed that well-fed females rarely eat the male, while hungry females often attack him.

In a roomy enclosure, place the male behind the female while she is eating. When they finish and the male climbs down, separate them right away.

My female laid an egg case without a male. Will it hatch?

A female can lay egg cases without mating, but unfertilized eggs won't hatch.

Can I release my mantis outdoors in autumn?

Adult native mantises naturally lay eggs in late autumn and die as it gets cold. If it's a native mantis from your own neighborhood, returning it near where you found it isn't much different from the natural course of things.

One that has lived in a warm room for a long time may die soon if you put it out on a cold day. Never release introduced species or mantises of unknown origin. We found no official guidelines on releasing them.

It died naturally in autumn.

Adults dying in late autumn is a normal part of the life cycle. You can bury it or keep it as a specimen.

If it laid an egg case, don't remove it. Keep it somewhere cool, like a shady spot outdoors, so the young hatch in spring. In a warm room they may hatch in winter.

Can I release the young that hatched at home?

Korean care sources suggest keeping only the few you'll raise when the young hatch in spring and releasing the rest near where you found the egg case. Release only native mantises from the same area, and only at the original spot. Avoid moving them to other regions or releasing large numbers bred over several generations.

A long, thread-like worm came out of its body.

That's a horsehair worm. It grows inside an insect's body and comes out when fully grown. It doesn't infect people. There's more in the horsehair worm story.