The European mantis (Mantis religiosa) is a large hemimetabolic insect in the family of the Mantidae ('mantids'), which is the largest family of the order Mantodea (mantises). Their common name praying mantis is derived from the distinctive posture of the first pair of legs that can be observed in animals in repose. It resembles a praying attitude. Both males and females have elongated bodies with two pairs of wings. The most striking features that all Mantodea share are a very mobile, triangular head with large compound eyes and their first pair of legs (the 'raptorial legs'), which is highly modified for the efficient capture and restraint of fast-moving or flying prey.
In Germany, M. religiosa is listed as Gefährdet [endangered] on the German Red List on the basis of an assessment from 1998. It is not supposed to be caught or held as a pet. At a global level, it is assessed by the IUCN as least concern.
Though females of M. religiosa are usually larger and heavier than males (7–9 cm versus 6–7 cm), the antennae and the eyes of male animals outsize those of the females. Along with the forward-directed, compound eyes, simple eyes also are found on the head. These three dorsal ocelli are also more pronounced in males than in females.
Males are often found to be more active and agile, whereas females are physically more powerful. Adult females are generally too large and heavy for their wings to enable a take-off.
Mantids show strong deimatic display from very early life stages on. This behavior can be observed throughout different groups of animals and is used to scare or startle potential predators to give the attacked animals a chance to escape. The deimatic display in M. religiosa involves wing spreading and bending of the raptorial legs to reveal two matched black eyespots with a yellow or white center at the base of the coxae (legs). It makes the animal appear much larger and more of a threat to the attacker. The black eyespots are also a distinct feature for species discrimination of the European mantis. Another unique feature of M. religiosa is its midline metathoracic ear (see Ultrasound avoidance). This “tympanal auditory organ” is an unpaired structure found on the ventral side of the animal on the metathorax between the third pair of legs. Unlike other sound-processing organs found among different groups of insects, the metathoracic ear has a high sensitivity across high and low frequencies and even ultrasound. Therefore, the authors call it a ‘true ear’.