Ink is communicating with his minions via symbols that only they and recently deceased poor Datu can understand. We now know via Datu that he was seeing his environment as if viewing it remotely from inside the back of his head. One could assume that the zombies are suffering from a " locked in syndrome " as experienced by stroke or some severely brain injured patients, that would be truly terrifying and cruel. They are being driven by their biological drives to feed etc. Ink must be able to communicate by voice, I don't think Kc would let him use telepathy. If the inkilings see him as their father, I can understand them obeying him. How would he control the behemoths ? One was patrolling Caine Hospital and how did all the other zombies suddenly arrive to attack Saul and the others, if they were not all already on site? I hope this will all be answered by Kc in the end. This is really bugging me.