There are around 30 different planetary cultures in the Zeta Reticuli star system, as well as Zeta-type beings living on planets outside of the system. They’re a human species that developed/evolved billions of years ago out of insectoid species, as opposed to Earth humans who have been developed out of mammalian bipeds. This is why the Zetas and Greys look so different. The Kebban Zetas were the original Greys, but there are also hybrid mammalian/insectoid Zetas such as the Essassanis, who are a combination of Zeta and Earth human genetics. The hybrid Essassanis can take their place at any level of Reticulan society, and work as teachers, healers, ship pilots and Commanders. The Zetas are totally egalitarian, with no discrimination between cultures or genders. The Mantids are Elders and Teachers to the Zetas, and are highly evolved souls.