Feeding Guide

The two rules

1. Prey size ≤ 1/3 the mantis’s body length. Bigger prey = injuries.
2. Frequency scales with stage. Young nymphs eat constantly; adults eat once every few days.

What you need to feed a mantis start to finish: a melanogaster culture ($15) for nymphs, a hydei culture ($15) as they grow, and an enclosure sized to the instar. A misting bottle ($10) covers hydration — droplets on the mesh are how a mantis drinks.

Everything else in this guide is detail.

Prey species by instar

L1–L2 nymphs

Melanogaster fruit flies (small wingless or flightless). Almost exclusively. L1 nymphs cannot subdue anything larger.

Source: a single fruit fly culture ($15) feeds a single nymph for weeks. One culture produces a steady supply of flies for about 3–5 weeks before it exhausts its media and crashes. Start a fresh culture every 2–3 weeks so you always have flies coming online — see our fruit fly culture care guide for the full routine.

How to offer: tap a small cluster (5–10 flies) into the enclosure. Replenish every 1–2 days.

L3–L4 nymphs

Hydei fruit flies (larger). Same source ecosystem as Melanogasters, just a different culture. Some keepers stick with Melanogasters and just offer more — also fine.

Optional: small houseflies (1/4 inch) once the nymph hits L4.

How to offer: 4–6 flies per feeding, every 2 days.

L5–L6 nymphs

Houseflies and bottle flies. Cultured houseflies are the workhorse — order pupae from a feeder supplier such as blue or green bottle spikes, hatch them in a deli cup over a week. New to feeders? See our feeder insects guide.

How to offer: 2–3 flies per feeding, every 2–3 days.

L7+ / Adults

Bottle flies (blue, green), moths, and appropriately-sized dubia roaches — depending on species.

Some species (Orchid, Spiny Flower) refuse crawling prey at every life stage. Others (African Twig, Double Shield) eat everything. Check the relevant species care guide — Dead Leaf and Ghost each have their own quirks too.

How to offer: 1–2 prey items every 3–4 days.

Prey-to-mantis size ratio

Melanogaster fruit flies are the practical exception — at ~0.2–0.25 cm they sit at or just above the 1/3 line for L1 nymphs, but their soft bodies make them safe to handle anyway.

Err smaller. A too-small prey item is a non-event; a too-large one risks injury.

Feeding frequency

Generally:

• L1–L2: every 1–2 days (or “always” — keep flies in the enclosure)
• L3–L4: every 2 days
• L5–L6: every 2–3 days
• L7+ adults: every 3–4 days
• Premolt: zero. Stop feeding the moment you suspect premolt (our molting guide covers the signs).
• Post-molt: wait until the mantis has hardened — moving normally, gripping firmly, colour back up. That’s about 24 hours for a nymph and 48 hours or more for an adult. If you’d rather have one number, wait 48 hours. It is too soft to safely subdue prey before that, and a feeder insect walking on a freshly molted mantis can injure it.
• Gravid females: feed slightly more — every 2 days vs every 3.

Skip a feeding if the abdomen is round and full. Don’t skip if the abdomen is thin and concave.

Reading appetite

A healthy mantis with good appetite will:

• Track a flying prey item with the head as it moves
• Adopt a stalking posture (lowered, body tense, raptorial legs cocked)
• Strike within 30 seconds of getting in range

A mantis refusing food might be (for a full walkthrough, see why your mantis isn’t eating):

• In premolt (most common reason; fasting lasts roughly 2–7 days for nymphs — longer for later instars — and 1–2+ weeks for adults approaching the final molt)
• Recently fed (already-full abdomen; check from below)
• Receiving the wrong prey (an Orchid offered stationary, non-fluttering prey)
• Too cold (below 70°F, most species slow dramatically)
• Old (adult females in their final weeks often refuse food)

Gut-loading prey

For optimal nutrition, feed your feeder insects nutritious food for at least 24 hours before offering them to your mantis. This is “gut-loading.”

Fruit flies: standard culture media is sufficient (already enriched with yeast and nutrients).

Houseflies: feed pupae a sugar-water mix as they emerge. Calcium dusting is borrowed from reptile keeping and is largely unnecessary for mantises — well-gut-loaded flies are enough.

Dubia roaches: feed them fresh greens, carrots, and high-quality dry insect feed for 24–48 hours pre-feed. Avoid spinach, citrus, or anything moldy.

How to dispense fruit flies without flooding your house

1. Tap the bottom of the culture against a hard surface to knock flies down.
2. Quickly invert the culture over the enclosure mouth.
3. Tap a few flies in. Re-cap the culture.
4. Use a small funnel or cup-with-vent if your aim is bad.

Loose flies in your kitchen are an inevitable cost of the hobby. Sealed cultures and fast hands minimize the damage.

Water

Mantises drink mist droplets off enclosure walls and perches. They rarely drink from standing water. A daily light mist on the walls (not the mantis itself) is sufficient hydration for almost all species.

The exception: very large adult mantises (Dead Leaf, Double Shield) may benefit from a shallow water dish if you observe them ignoring mist droplets. Keep any dish extremely shallow (a bottle cap) and add a pebble or sponge so the mantis can’t drown — most keepers skip the dish entirely and rely on misting.

What not to feed

• Crickets — any species, any life stage. Not because a mantis can’t eat one; it’s a disease call. Crickets are the most disease-prone feeder in the hobby — densovirus die-offs and gut parasites are common, and a sick cricket can pass problems straight to your mantis. We feed flies and dubia roaches instead, which carry far less risk. This is our policy for every mantis we sell.
• Wild-caught insects. Pesticide exposure is unpredictable and often fatal.
• Mealworms. Tough exoskeleton and hooked mandibles — risk of mantis injury.
• Spiders, ants, ladybugs, fireflies. Wild-caught, and some carry toxins or fight back.
• Pinky mice. Not needed for most mantises (some large breeding females take one occasionally — the exception, not the rule).

Stick to flies, fruit flies, and dubia roaches and you’ll have no problems.