Final answer:
When Peter cut off Hook's hand, he placed it on a rock. Hook hears the crocodile ticking when danger is close.
Step-by-step explanation:
When Peter cut off Hook's hand, he placed it on a rock. In the story, Hook is said to hear the crocodile ticking whenever "danger" is close. This is because the crocodile had swallowed a clock, and its ticking sound acts as a warning for Hook.