Rogue cuckoo birds stole nests, kicked out other chicks, to be fed by unsuspecting parent birds

 

A cuckoo can dart into an unattended nest, snatch up an egg, lay a close copy and be gone within 10 seconds. After hatching, some cuckoo chicks (though not the great spotted) instinctively shove their foster siblings and remaining eggs out of the nest, so as to have all the food to themselves....

In truth, if the cuckoo were human, it would be considered a rogue, a fraudster and, not to put too fine a point on it, a cheat.

The only British bird not to rear its own young, the common cuckoo makes no nest of its own, instead using other birds to handle incubation and feeding duties. Favoured host species — or dupes — include meadow pipits, robins, dunnocks, reed warblers, pied wagtails and willow warblers. The targeted hen birds proceed to hatch the egg and rear the cuckoo chick, even after the hatchling has ejected all the other, ‘legitimate’ eggs or chicks from the nest, sending them to their deaths.

Above were copied from various sources in the internet, including wikipedia.

What is the moral of the story?