Prantis III is a small hot jungle planet with large growths of massive exotic plant life. The moist air is refreashed by daily torrential rains. Small flying insects and other small creatures frolic in the deep green, at home with the constant smell. About 2/3's of the planet is jungle the other 1/3 is made up of deep lakes and rivers.
Their is only one city on the planet, built into the one and only mountain on the planet. The mountain is actually an artificial construct built by the natives. It is so big that it can be seen from space. Here, under the ground, they have built their civilization.
All Prantis enter the city to learn and those that are found to be good enough are rewarded with jobs in the city. All the rest either find jobs off world or return to the jungles to work at food gathering.
Even those Prantis who are not good enough to get jobs in the city are for the most part superior engineers, scientists and craftsmen to those found off world.