A Fly sat atop a Mule and said he should go faster or the Fly would bite him. The Mule did not care as he only answered to his driver.
Ignore complainers who have no influence.
Townsend version
A fly sat on the axle-tree of a chariot, and addressing the Draught-Mule said, “How slow you are! Why do you not go faster? See if I do not prick your neck with my sting.” The Draught-Mule replied, “I do not heed your threats; I only care for him who sits above you, and who quickens my pace with his whip, or holds me back with the reins. Away, therefore, with your insolence, for I know well when to go fast, and when to go slow.”
Mula et Crabro
Crabro, involans in caput clitellariae mulae, “Quin moves te,” inquit, “et gressus incitas! An ego te, lentam viatricem, nisi pergis, instigabo?” Cui mula “Non ego te curo,” inquit, “sed fustes et stimulum illius, qui me sequitur,” mulionem significans, “a quo si mihi quiete esse liceat, tuos facile, mi crabuncule, impetus pertulero.”
Perry #498