What is Wrong With Melbourne's Flies?

fly

What is wrong with the flies near Flinders St, Melbourne? Picture a fly. You're probably thinking of a buzzing insect, zipping around from wall to wall. You take a swipe at it, but it easy avoids your hand. This is the typical behaviour of a fly. But the flies near the Yarra River are sluggish and completely un-fly-like. Sticky flies are nothing new, but these insects take it to a new level. If one lands on your shirt and you swipe at it, the thing doesn't move. The city flies just stay put. The only way to get them off is with a spoon.

I saw one at Federation Square walk three metres across a bench top. A few people shewed it as it strolled past, but it wasn't phased and kept on going. What was it doing walking three metres? If you scale it up, that must be like walking a mile for a human.  Since when do flies take leisurely strolls? It's a fly; not a walk.

And when the city flies do live up to their name and take flight, they're so painfully slow. They hover about as though they're floating through water. It's so annoying and when you try to shew it away, the fly ignores you and gets up in your grill as though it's saying in a sedate, monotone voice, "Hey there, Simon. Whacha doin'? Mind if I take a look?"

Suburban flies don't behave this way. There must be something dulling the city fly population's wits. My hunch is that it's the Yarra. I know flies eat dung all day, but that is far preferable to drinking, swimming in or even looking at the water from the Yarra River.

If there is a scientist or fly expert out there, please fill me in.