what is the predator of a praying mantis
Mantises are generalist predators of arthropods
Mantis
Mantises are generalist predators of arthropods. The majority of mantises are ambush predators that only feed upon live prey within their reach. 
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Mantis [SEP] Diet and predation
Mantises are generalist predators of arthropods. The majority of mantises are ambush predators that only feed upon live prey within their reach. They either camouflage themselves and remain stationary, waiting for prey to approach, or stalk their prey with slow, stealthy movements. Larger mantises sometimes eat smaller individuals of their own species, as well as small vertebrates such as lizards, frogs, fishes, and particularly small birds. Most mantises stalk tempting prey if it strays close enough, and will go further when they are especially hungry. Once within reach, mantises strike rapidly to grasp the prey with their spiked raptorial forelegs.