Book IV, 37: On the Cuckoe

The idle Cuckoe, having made a Feast
On Sparrowes Eggs, layes downe her owne i'th' Nest;
The silly Bird she ownes it, hatches, feeds it;
Protects it from the weather, clocks and breeds it;
It neither wants repose nor yet repast,
And joyes to see her Chicken thrive so fast:
But when this gaping Monster has found strength
To shift without a helper, she at length
Not caring for that tender care that bred her,
Forgets her parent, kills the Bird that fed her:
The Sin we foster in our bosome, thus
Ere we have left to feed it, feeds on us.