Mantis or sometimes known as mantodea or mantises, are small insects. They mostly live in tropical habitats and they are very common as there are 2,200 different species of mantis.

Diet
Mantises generally eat insects for their primary diet but sometimes feel the need to have a larger meal as they have been known to eat lizards, frogs, birds, snakes, fish, and even rodents! Even with all this most species of mantises turn to cannibalism.
Defense
When mantises are under attack they'll spread their forelegs and the wings out to look more threating and imposing to creature which is attacking it. Some species off mantises have bright colours and impolding patterns for this purpose but the creature attacking them still dosen't get a hint then the will kick the forelegs out and have a attempt for a bite. Some species even make loud hissing noises to scare the creature. Some mantises are able to detect a echololation (this is a noise mde by bats) when the frequency increases very rapidly the will stop flying horizontally and drop vertically flying in a descending spiral downwards lading safely on the floor below.
Reproduction
Sexual canniblism is very common when mantises reproduce. The female often starts to feed by biting off the males head while mating . It was thought that this theory was used by females to enhance fertilisation, but there is no evidence to prove this. Females usely lay their eggs in late autumn. They lay from 10 - 400 eggs!
This is a small clip showing a prey mantis devouring a mouse. Please click on it.
http://www.youtube.com/watch?feature=player_detailpage&v=pNcIUIULafw