These small but strong pincers quickly chop even large prey to bite-sized fragments suitable for swallowing. Greedy mantids can sometimes grab a second prey while still munching on the first one. A common misconception is that female mantids always eat their partners during or after mating. This behavior, aptly named sexual cannibalism, does not occur in all species or in all matings. In fact, in only one species, the European mantid, is this behavior noted and then only infrequently and while being closely observed in artificial or captive conditions.
Mantids are beneficial because they consume other insects.
However, their impact in the garden and landscape is probably negligible. True, they do prey on pests, but they will eat virtually anything they can catch. They do not discriminate between beneficial and harmful garden insects and will eat their siblings, other beneficial insects, butterflies and pollinators such as bees. Mantids may not provide much pest relief in your garden but they are an incredible source of amazement.