Things are a bit cuckoo in this part of birdland:

Cuckoos live what seem to be lives full of deception and murder. As adults, they lay their eggs in the nests of other birds. (Why raise your own chick, when you can dupe others into doing the work for you?)
Cuckoos typically hatch only one offspring at a time. And when they do, the interlopers promptly push the other eggs out of the nest, killing the host birds’ true offspring.
For the newborn cuckoo, masquerading as multiple chicks can be difficult, especially when the lone, giant nestling replaces the usual clamoring brood.

Do any human analogues to this behavior come to mind?