The Flea and the Ox_英语寓言故事

a flea thus questioned an ox:
"what ails you, that being so huge
and strong, you submit to the wrongs you receive from men and
slave for them day by day, while i, being so small a creature,
mercilessly feed on their flesh and drink their blood without
stint?'
the ox replied:
"i do not wish to be ungrateful, for i am
loved and well cared for by men, and they often pat my head and
shoulders."
"woe's me!"
said the flea; "this very patting which
you like, whenever it happens to me, brings with it my inevitable
destruction."