Mantids are a group of 1,800 carnivorous insects (Order: Mantodea). Most mantids are from tropical countries although a few do occur in cooler climates. Their closest relatives are the stick insects, grasshoppers and cockroaches. Like their relatives the mantids undergo simple or incomplete metamorphosis; they do not have a maggot or caterpillar but go through several stages all of which look like miniature, wingless adults.
Young mantids should be fed on fruit flies , aphids or other small insects. They do well if supplied with as much food as they can eat although they can last quite a while without food.
As they grow they can be given larger prey, almost any insects (for example, blue bottle flies, grasshoppers, crickets, cockroaches) will be eaten. Some species will happily tackle prey as large as themselves. However, you should make sure that any insects that are not eaten do not chew the legs or wings of your mantid.
If you keep live food for your mantid then you should also ensure that the live food is kept in appropriate conditions (adequate space, correct temperature and humidity and access to food and water).
Many species are very aggressive towards each other and if kept in groups they will eat each other especially as one or two become slightly larger than their brothers and sisters.
As the mantis grows it will shed its skin several times, becoming larger at each stage. Initially a small container such as a yoghurt pot will make suitable cage. As the mantis grows it can progress into a jam jar or milk bottle and finally into a sweet jar. The top of the yoghurt pot can be covered with clingfilm. A small hole can be made through the clingfilm to allow food to be put in. The hole can be plugged with a piece of sponge which will allow air to enter. A similar sponge plug can be used in the neck of a bottle, jars should have lids with holes drilled in them.
Whatever type of cage is used a stick or branch should be provided for the insect to hang from when it sheds its skin and the distance from the top of the branch to the floor must be at least three times the length of the insect. Many Praying mantids are from tropical origins and therefore need to be kept warm, as a general rule 20°C to 25°C will be ideal.
Mantids do not usually need to drink. However if they are kept in a heated cage a small dish of water is a good idea in order to provide some humidity, alternatively the cage should be sprayed with water each day.
Sexing mantids is difficult when they are small but fairly easy when adult, eight segments can be counted on the underside of the abdomen of a male and six on that of the female (in some species the end segments are difficult to see and only seven or five may be counted).
After two or three weeks as adults the mantids can be mated. Both should be fed as much as they will eat for several days before the male is introduced to the female's cage. It is advisable to use a large cage for the mating and feeding them well beforehand is essential otherwise the female will eat the male. Mating may occur immediately or it may take the male a day or so to make his approach. Mating may last a day or more so it is a good idea to keep the cage supplied with food so the female can eat while mating. The male should be removed as soon as mating has finished.
The eggs are produced in an eggcase called an ootheca this may produce 30 to 300 young mantids depending on the species. The ootheca is a frothy mass created by the female, the froth hardens to form a tough case for the eggs. Hatching usually takes between 3 and 6 months. The young may hatch all at once or in batches over a period of several weeks.
The ootheca should be suspended at least 5cm above the floor of the cage. When the young hatch they hang by a thread from the ootheca until their skin hardens off. The female will eat a lot and become very fat before laying an ootheca on a branch or side of the container if she is already fat she may well lay her first ootheca the day after mating.
She will lay several oothecae, usually about six, but only needs to be mated once. The young nymphs can be housed together for a time but the cage must be very large with plenty of hiding places and an excess of live food must be provided to prevent cannibalism. The mantids should be housed separately after the second or third moult.
Mantids will live for 12 to 18 months and the oothecae can also take several months to hatch.
Some species of mantis are parthenogenic so can produce a viable ootheca without mating.
Overwintering mantis oothecas (egg mass)
If you live in a location where mantids occur naturally you may find mantis oothecas (see the photograph on our Mantodea page) in the wild. People sometimes wonder how the eggs within the egg mass survive over winter. In the case of the mantis, the eggs will be buffered from extremes of temperature by being in the protective egg case (or by the position of the oothecae).
However, people occasionally bring mantis egg masses indoors to "protect" them over winter. Unfortunately the warmth can cause the nymphs to emerge early and be unable to find any food. Instead, if you want to keep and observe the ootheca, you should keep it in an unheated building (like a shed) and let the nymphs emerge at the correct time.
Praying mantids undergo incomplete metamorphosis. Sometimes, often if their cage is too dry, a mantis may have trouble shedding its old skin and will lose a limb in the process of moulting. If this happens it is possible for a mantis to regrow the lost limb but only when they moult again. This means that, if your mantis is an adult (i.e. if it's got wings), then it won't be able to regrow the lost limb.