The Shepherd and the Sheep

by Aesop

A SHEPHERD, driving his Sheep to a wood, saw an oak of unusual size, full of acorns, and, spreading his cloak under the branches, he climbed up into the tree, and shook down the acorns. The Sheep, eating the acorns, frayed and tore the cloak. The Shepherd coming down, and seeing what was done, said: O you most ungrateful creatures! You provide wool to make garments for all other men, but you destroy the clothes of him who feeds you.

Moral:
The basest ingratitude is that which injures those who serve us.