The point was this: Tikki decides what she will do, where and when she 
will kill, if she will kill. No one else makes that decision. No one. 
That is her absolute rule, her law. All must obey. Even she. Even instinct. 
Ruthlessly enforcing that law is how she has managed to survive for so long. If 
she had killed every time the desire arose, she would have been like a creature 
run amuck, and humanity would have banded together long before now to hunt her 
down and destroy her.