What do mantises eat?
The European mantis (M. religiosa) is a carnivorous ambush predator that actively scans its environment and feeds on most insects that are not too large to be captured by rapid extension of its raptorial legs. Only living and moving prey is captured and consumed immediately using their powerful mandibles. Grasshoppers seem to be rather popular, probably because of their type of movement (flying or leaping), but crickets and cockroaches are also frequently preyed upon. The attack or consumption of Mollusca, Aranea, Myriapoda, or Oligochaeta is also not unknown.
Caught prey gets trapped between the spikes on the femora and tibiae and is now immobilized. The mantis then starts eating the still-living and preferably moving prey. Some years ago, the general opinion was that they killed their prey with a bite in the neck before consuming it, but current observations do not support this; the animals just start eating the body parts closest to their mouths.
M. religiosa is also known to eat conspecifics outside a sexual context. Because of this, they usually need to be kept isolated from each other in captivity.