Some researchers have advanced the theory that the human race was created by an alien race for mining. But few people know that before people the Anunnaki used other aliens as labor force.
It is said to have been a race of aliens with a slightly lower level of technical development than the Anunnaki. The name of this race is found in ancient manuscripts - Igigi, that was the name of the aliens who worked for the Anunnaki before the creation of people.
It is believed that the Igigi worked both on Earth and in its orbit, where there were factories for processing minerals. After a while there was a revolt and the servants of the Anunnaki rebelled against their masters. Many tools for extracting resources were destroyed, they even attacked the houses of the owners. As a result, the uprising ended in the defeat of the slaves. Although the Igigi were a highly developed civilization, this did not help them defeat the Anunnaki.
The Anunnaki got rid of the rebellious slaves and began to experiment with the genes of the terrestrial fauna, combining them with their own. The ultimate goal of this project was to breed a new race of slaves, which they eventually managed to accomplish.