How could Godzilla sense Mechagodzilla?

Question

Madison encountered Mechagodzilla at the Apex facility, and says to Bernie:

This is why Godzilla attacked the Apex facility. They're trying to replace him.

Mechagodzilla had never left the Apex facility before, so how could Godzilla have sensed it?

Answer 1

Godzilla isn't sensing Mechagodzilla, rather he's sensing Ghidorah's severed head, which is used by the pilot, Ren Serizawa, to telepathically link to and subsequently control Mechagodzilla.

Given that the skull is kept at the Apex facility, Godzilla would naturally head straight there, regardless of where Mechagodzilla is.