Pretty idyllic scene, right? Couple of ducks, doing ducky things, in the cove, their safe haven. WRONG! Look up a bit north...here's our resident alligator, silently stalking his prey...
It's the Law of the Jungle.
"The Law of the Jungle, which never orders anything without a reason, forbids every beast to eat Man except when he is killing to show his children how to kill, and then he must hunt outside the hunting grounds of his pack or tribe.
...Mowgli was taught the 'Stranger's Call,' which must be repeated til it is answered, whenever one of the Jungle People hunts outside his own grounds. It means, translated, 'Give me leave to hunt here because I am hungry.' And the answer is 'Hunt then for food, but not for pleasure."'
Rudyard Kipling The Jungle Book