Crows

Black birds roosted on a tree
counting them, you could tell there were three.
"Let it be known," they said with a caw
"that here despair is the law!"
The other birds chirped at this declare,
thinking they had no reason to listen to those crows over there.
One by one, overnight,
they become overcome with a terrible plight:
each one became sad,
forgetting the joy each one once had,
it is on that next day that you must know,
all of the birds had become crows.