Many host species can identify foreign eggs based on color, size, or patterning and will pierce the egg or drag it out of the nest.

: A description of the disproportionately large, fast-growing size of parasitic chicks compared to their host siblings.

The phrase "in be full" points to the endless hunger drive that defines these young parasites. A brood parasite's survival relies entirely on keeping its stomach full at the expense of everyone else in the nest.

Meet the Channel-billed Cuckoo, the World's Largest Brood Parasite