Caring for an Ootheca: From Egg Laying to Mantid Offspring

Suddenly, you’ll see a foamy structure hanging from a branch or under the lid: Your praying mantis has built an ootheca. Her eggs are inside. Now begins an exciting waiting period—and the best opportunity to prepare for the potential offspring at your leisure.

What should stay with the female, and what should go in its own container? How moist does it need to be, and what kind of food do the tiny mantises need? Here, we’ll guide you from egg-laying through the first few days after hatching. The species of your praying mantis is always the deciding factor.

What is an ootheca—and is it fertilized?

An ootheca is the protective egg case of a mantis. When laying her eggs, the female produces a soft, foamy mass that subsequently hardens. The shape and size vary depending on the species: Some egg cases are elongated, while others appear more rounded. Behind this unassuming casing, a few or a large number of nymphs may develop.

An ootheca alone does not prove successful reproduction. Even unmated females can lay eggs. For most mantises kept in captivity, fertilization is necessary; there are exceptions for certain species. Observing a mating increases the likelihood of offspring, but does not guarantee hatching. Therefore, do not cut open the egg case to check.

A freshly laid ootheca: stay calm for now

Leave the female undisturbed while she lays her eggs. Take a photo of the completed clutch in its original location and note the species and the date of laying. The photo will help you maintain the original orientation later on. If the female was already an adult when you acquired her, also note whether a previous mating is known.

Wait until the shell has hardened before moving it. As a general guideline, this takes a few days—often about three to five. Do not press on the clutch to test its firmness. If it is attached to a removable twig, you can move the twig—along with the ootheca—later. This is easier than removing the foam nest.

If it is stuck directly to a pane of glass or the lid and the carrier cannot be removed, do not try to pry it off by force. Instead, check how it is attached by taking a photo. Plan to keep the young in a separate enclosure: The adult female may eat them.

Storing the ootheca: Air, support, and space at the bottom

The hatching container needs a lid that closes securely and fine-mesh ventilation gauze. Small nymphs and their food flies must not be able to escape through any gaps. At the same time, air must be able to circulate. A suitable container you already have will suffice; you don’t necessarily need a special incubator for this.

Secure the branch firmly and in the same position as before. There must be free space beneath the hatching area: When they emerge, the young will initially hang downward. A common guideline is to leave at least five centimeters of free space; for larger species, allow more accordingly. Twigs, substrate, and decorations must not block this path.

The size of the container also depends on the species and the expected number of young. A small container is not a long-term rearing solution for a large clutch. Avoid exposed adhesive surfaces. We’ll explain the mounting options in the next section. Especially for your first clutch, an intact laying branch is the clearer solution.

If you need a new housing solution, consider a BraPlast container with dual ventilation. Choose the height based on the available space under the nest and check that it’s secure for your young. The container is not a substitute for separating the young at a later stage.

Attach the ootheca to the BraPlast lid

You can attach a detached, hardened ootheca to the inside of the lid of a BraPlast container. This leaves space beneath the clutch for the hatching young. If it’s still firmly attached to a twig, you can attach the twig along with the clutch instead. You don’t need to detach the ootheca specifically for this.

The key is proper placement: Secure the clutch to its original attachment surface and leave the hatching area completely clear. Both vary depending on the species. A photo of the laying site will help you get your bearings. Use only a small amount of adhesive and do not compress the egg casing.

Silicone, hot glue, or adhesive pads?

When keeping mantises, people use silicone, hot glue, and moldable adhesive pads such as UHU Patafix. These are practical methods for securing the oothecae; they are not a blanket manufacturer’s approval for live oothecae. Which method you choose also depends on the shape of the ootheca and your experience.

Silicone: A small dot on the adhesive surface holds the clutch in place on the lid. Work outside the occupied container, leave the hatching area clear, and follow the curing and ventilation instructions for the product you are using. From our product range, you’ll find the Hobby Silicone Adhesive listed below. It is suitable for terrariums only after it has fully cured; this does not imply specific approval for direct contact with oothecae.

Low-temperature hot glue: First, apply a small dot to the lid and let it cool significantly until it’s still tacky. Then carefully position the original adhesive surface onto it. Do not apply fresh hot glue directly to the fabric. Let the bond set before turning the lid over.

UHU Patafix: Use a small amount as a moldable fastener on the adhesive surface. Do not leave any exposed sticky areas in the running or sliding areas. Avoid applying pressure to the clutch and check that it is secure. Again, there is no specific manufacturer approval for oothecae.

Attach it to Styrofoam and check that it stays in place

Pinning the ootheca to Styrofoam is also a common practice among keepers. Neither the egg chambers nor the hatching zone should be damaged in the process. Because the appropriate spot can be difficult to identify depending on the shape of the ootheca, this method is best suited for experienced keepers. Don’t just pierce through the clutch. If in doubt, ask for guidance on how to secure the ootheca for your specific species.

Finally, carefully check to see if the fastening holds without pulling on the clutch. The space described earlier remains beneath the hatching area. Feel free to open the lid later, holding it so that you don’t bump the ootheca. If young are already hatching, leave the container undisturbed for now.

Temperature and Humidity: Which type do you keep?

A single numerical value for all oothecae would be convenient, but it won’t reliably help you. Refer to the care guide for your species, and if you’ve purchased a clutch, ask about the conditions it was kept under so far. Note the temperature on the container itself, rather than relying solely on room temperature. Direct sunlight can quickly heat up a small container.

Humidity depends on the interplay of watering, ventilation, and temperature. Do not keep the container either constantly wet or completely dry without any control. If necessary, moisten part of the substrate without soaking the ootheca. If the walls remain constantly fogged up or mold forms, check the amount of water and the air circulation. Adding more animals to the container does not replace this check.

Ghost Mantis: Patience and Tiny Ant Look-Alikes

For the ghost mantis (Phyllocrania paradoxa), oothecae are cared for under conditions similar to those for the adult insects. Breeders often cite a period of about six to eight weeks until hatching. This is not a guaranteed timeframe: temperature and developmental stages can affect the waiting period. Incidentally, the newly hatched nymphs initially look more like small, dark ants than like dried-up leaves.

Indian Giant Mantis: Expect a Large Brood

For Hierodula membranacea, breeders report an incubation period of about five to six weeks at 25–30 °C. A single clutch, for example, can produce 80 to 200 young. Therefore, plan for space, food, and future buyers before hatching. These are general estimates based on experience and are not guarantees for your specific clutch.

Orchid Mantis: The little ones look completely different

For the orchid mantis (Hymenopus coronatus), breeding experience indicates a development period of about four to six weeks at 25–30 °C. The newly hatched nymphs are initially reddish with dark patches—the familiar white-pink appearance develops later. Keep small fruit flies on hand. Do not try to speed up hatching by applying additional heat: Development times are guidelines, not a countdown.

Does the ootheca need a winter break?

Please do not place an unidentified clutch of eggs in the refrigerator as a precaution. For some species from temperate regions, a developmental dormancy period is a natural part of their annual cycle. For other species, however, this treatment is not appropriate. The duration and temperature must be tailored to the specific species and its origin; therefore, the rule of “eight weeks in the refrigerator for all” is unsuitable.

Also, “tropical” doesn’t mean that there are no seasons at all in the species’ place of origin. If you’re not sure which species the ootheca came from, find that out first. Simply changing the temperature is not a sensible way to trigger hatching.

Your Checklist: Today, While You Wait, and on Hatching Day

• Today: Record the species, laying date, and known mating pair. Take a photo of the clutch at the laying site and let it harden first.
• While waiting: Check the temperature, humidity, and ventilation in the container. Note any abnormalities instead of constantly changing the conditions. Prepare rearing containers and a sufficient supply of fruit fly cultures in advance.
• On hatching day: Ensure there is enough space under the ootheca and let the animals emerge undisturbed. Only move the young that are walking steadily. Then offer suitable prey and check to see if it is being eaten.

Hatching Begins: What You Should Prepare Now

After weeks without any visible changes, the clutch may suddenly start to show signs of movement. Let the fry emerge on their own and harden off. Do not pull them out of the shell or shake them out. Some clutches do not hatch completely all at once; therefore, do not discard the ootheca immediately after the first young emerge.

Have small, well-ventilated rearing containers and suitable live food ready in advance. As soon as the animals can walk and grasp objects confidently, you can let them carefully climb onto a thin twig and transfer them one by one. Do not squeeze them between your fingers. Keeping them separately makes it easier to monitor their feeding and prevents siblings from eating each other.

Offer small, active young animals suitable fruit flies and observe whether they can handle them. The small fruit fly “Ant” and the “Turkish Glider” are two forms of Drosophila melanogaster. You don’t need both at the same time. Start by giving a manageable portion and check to see if they’re eating it.

For young mantises that can already catch larger prey with confidence, the Large Fruit Fly and the “Big” Large Fruit Fly are good options. Both belong to the species Drosophila hydei. Choose based on the actual size ratio, not just on the name of your mantis species.

Answers to Frequently Asked Questions

Does an ootheca need its own lamp?

Don’t buy an additional lamp just for the ootheca. First, check the conditions for your species and the measured temperature at the location. Lighting is no guarantee that the eggs will hatch. Avoid direct sunlight and uncontrolled heat; after hatching, the young need suitable housing conditions.

How can I tell if any more will hatch?

You can’t tell for sure just by looking at them from the outside. Compare the waiting time so far with what’s typical for that specific species, and take the temperature into account. If the eggs haven’t hatched, the species name, laying date, information about mating, and photos can help you assess the situation. Exceeding the expected incubation period does not automatically mean that all the eggs have died. Opening the eggs or spraying them vigorously is not a reliable test.

If something stands out during development

What should I do if I find mold?

First, check the substrate, condensation, and ventilation. Carefully remove any loose, moldy material without damaging the clutch. Do not apply any household cleaners to the ootheca. If the shell itself is affected, send us a clear photo and describe the conditions so far.

The ootheca is torn or dented—what should I do now?

Handle it as little as possible, and do not repair the crack with glue. Take a photo of the damaged area and note the species, age, and conditions to date. It is not possible to determine with certainty how many eggs are affected based on the outer shell alone. Have the situation assessed by an expert instead of opening the clutch to check it.

A hatchling is stuck while hatching. Should I help?

When they emerge, the little ones initially hang upside down; that alone isn’t an emergency. Don’t pull on an animal or spray it directly in an attempt to free it. First, check whether the hatching passage is clear. If an animal appears to be stuck, a clear photo or short video, along with the current rearing conditions, can help when quickly consulting an experienced breeder. Empty exoskeletons may remain behind and should not be mistaken for a live animal that is stuck.

Do I have to buy new accessories right away?

No. First, check your existing containers: make sure they’re tall enough, well-ventilated, securely closed, and easy to monitor. Only add what’s missing for hatching and subsequent rearing. The most important supply is the right food, which must be available when needed.

Still unsure? Feel free to ask us your question in the comments section below the article.