Even the experts reckon the flies are unpleasant at the moment.

Department of Primary Industries' entomologist Joanne Holloway reckons the flies seem to be "more annoying than usual".

Dr Holloway suspects that the dry, windy conditions could have something to do with it.

She said the dry weather means there is more animal dung lying on the ground.

"We've had a lot of wind, and that brings the flies in," Dr Holloway said.

"They're coming in from the warmer areas. The temperatures have helped them breed."

Dr Holloway has also noticed that the flies this year seem to be a little smaller.

"When they are smaller, they tend to get more anxious. They need more protein," she said.

Annoyingly, they are going to try to get that protein from us, or at least from the moisture on our skin.

"They're taking liquid up, like a sponge. They're mopping it up," Dr Holloway said.

"If we've got reduced stock out there - you'll notice this when you're out in a paddock - the flies will find you because you're the only one in the paddock and they're really good at sensing you. But if there's a lot of people are animals there, you won't notice it as much because you've got more targets."

Charles Sturt University Professor of Applied Ecology Geoff Gurr said flies were traditionally bad at this time of the year.

"It's largely a seasonal effect. Flies are a little bit like us - they don't like it too hot or too cold," Professor Gurr said.