My headcanon is that Olmecs are sensitive to light (which is why they move or attack once night has fallen).

That's why they opted to build their new base in the heart of another mountain. There, they explored the most powerful energy source of all: nuclear fusion. In this way, they were able to reproduce on Earth the reactions that take place inside the sun, creating their own “sun”. I see Calmèque as one of the Olmecs with a more developed scientific mind and curiosity. While Ménator focuses on cellular biology to extend the Olmec's lifespan, Calmèque focuses on the study and understanding of high-temperature plasmas and their confinement by magnetic and electric fields.

A century later, the Olmecs created the first nuclear fusion reactor, generating colossal amounts of energy that satisfy their energy needs. Thanks to this, Ménator is able to electrically stimulate the fusion of two previously atrophied and dysfunctional Olmec reproductive cells (I headcanon the Olmecs as hermaphrodites, in which both reproductive systems progressively atrophied over time, hence the Olmecs are sterile). This way, they are able to ensure their descendants (although the embryos develop in incubating machines) and secretly become the most developed civilization on Earth :)