We found an answer here.
The diet of a praying mantis most often includes various species of insects - including mosquitoes, flies, grasshoppers, beetles, butterflies, moths, spiders, roaches, bees, dragonflies, etc. Other than these insects, some praying mantis species also feed on lizards, frogs, rodents and birds. Almost all the species of mantis feed on insects, but those which can grow up to a length of 10-12 cm are generally the ones who take on birds, rodents and other creatures of their own size.So, no, we can't keep it as it will eat our crickets. We released it to our rose of sharon bush.
How can you tell a girl from a boy?
The difference between a male and female praying mantis is that the female is larger and the abdominal is larger than a males abdomanal.
Adult female Mantises are larger than adult males. That's one way to tell them apart.