A little old lady buys a pair of parrots, but cannot identify their sexes. 
She calls the shop, and the man there advises her to watch them carefully 
and all would become clear in time.

She spends weeks staring at the cage and eventually catches them doing 
what comes naturally. To make sure she doesn't get them mixed up again, 
she cuts out a ring from a piece of cardboard and puts it round the male 
parrot's neck.

A while later, the local priest visits the old lady. The male parrot takes 
one look at the father's collar, wolf whistles, and says, "I see she 
caught you at it, too."