Let's try to understand what causes hatching
Since Chapter 114 Page 3, we are given good reason to believe that what causes hatching is at least predictable:
The pages leading up to page 3 are in the spoilers below:
So we know that Hatching very likely is not random if a researcher knows so with such certainty.
Miki from Hexenjagd has said in Chapter 124 page 9 that, "the time of hatching can be affected by the host's emotional state," which suggests that the cause is related to emotions or particular feelings.
I only remember seeing hatched Drasil's twice: Hatsuna's and Rurumi's.
Before Rurumi's hatches, she says that her brain's about to burst, and maybe the time before she hatched can give us hints about the conditions needed for hatching.
What do you think, and what did you observe?
Edited by The Warrior Gentleman, 26 November 2014 - 10:23 PM.