Praying Mantis

The praying mantis is described as a primitive insect, which surprises me. It clearly has stereoscopic vision with its two green compound eyes in the front of a head that moves freely on the neck to face squarely the object of interest. It can see objects more than 20cm away. It has an"ear" set between the two rear legs. It invariably eats its male suiter, usually during copulation that continues well after the head and thorax have gone. The young hatchlings look similar to the adults, but pass through a series of about 5 instars to reach adulthood and sexual maturity. There is no mention of the three receptors between the eyes. I will look further, but I suspect they could be UV detectors.