Answer:
A reaction to being spooked that takes its name from waterfowl
What has a big mouth, yet never speaks?
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
The root tops the trunk on this backward thing, that grows in the winter and dies in the spring.
Feed me and I live, give me drink and I die.
A town has only two barbers. One of the barbers has a nice, tidy haircut, and the other has a shaggy, messy haircut. Which barber should you go to?