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 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.
The great variation in the coloration of M. religiosa from different shades of yellow, brown, green, and sometimes black has been the cause of numerous hypotheses and studies for over 100 years. However, no generally accepted answer about reason, benefit, or mechanism of the coloration or the change of coloration has been found.
Di Cesnola observed in 1904 that green mantids were found on fresh green grass, whereas brown individuals seemed to prefer brown grass burned by the sun. When forced to change the location as to no longer match their coloration, almost all the ‘not matching’ animals were killed by predators such as birds. This indicates a camouflaging purpose of the coloration.
Przibram also observed in 1907 that a change in temperature can trigger a change in coloration: animals that hatched in a cold environment turned green after moulting when heat and sunlight were provided. Without the change in temperature and only a change in the color of the background, no change in coloration occurred. This finding contradicts with Di Cesnola, who claims to have observed the animals within the same time and location (and therefore the same temperature).