What to do about flies biting my dogs ears?

A coat of Vaseline often helps… the flies don’t like it and it helps the ears to heal if they’re kept moist.
Some dogs will get hundreds of bites a day for weeks at a time. Anyone that has ever been bitten by a horse fly knows how painful the bite is! The bite wounds attract flies which may lay their eggs in the damaged tissue. These will later hatch into maggots… so you surely want to prevent that!
Clean the ears with warm soapy water on a cloth… don’t get water IN the ear… a cotton ball in the ear will prevent water from running in. Water in the ear can cause an ear infection. Wipe dry and put antibiotic cream or petroleum jelly on the parts the flies are bothering. You might even need to remove the dog from the area if there is other livestock or dumpsters in the area attracting the flies. Since the flies are the worst during the hottest part of the day, bring them indoors during that time if possible.
You defintitely want to deal with it before you have maggots… once those occur it’s time to visit the vet.