Answer:
A reaction to being spooked that takes its name from waterfowl
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around
A nut cracker up in a tree.
What does a WW1 Trench, A Submarine and a Popular Phone App all have in common?
I never was, am always to be. No one ever saw me, nor ever will. And yet I am the confidence of all, To live and breath on this terrestrial ball.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.