Swap the graphics of the flies with a more menacing creature, i.e. an alligator, a mutant frog, a "swamp thing", rat-people; just something, anything that appears to be more menacing than flies. Not even change their attributes, etc. Just different graphics.
I find it absolutely ridiculous how certain people who decided to play fighter characters are dogged by the game and get their ass kicked by a swarm of flies, when their character is new to the game. They can also create absolutely ridiculous situations in role-play.
- A: What are you?
B: I am a warrior from the lost kingdom!
A: So why were you running from flies?
B: I, ehrm, didn't eat my vegetables lately.