"Flies are cold blooded, so they always try to get heat from an external source. That's why you'll also see them buzzing around lights, it's like a source of adrenaline for them, so it takes quite a lot to knock them down when they're running at maximum capacity," Foster said.
"The hotter it gets, the harder they are to get rid of. Blow flies tend to be more rural, but in town you get the house flies. The environment will dictate what you'll get depending on where you are."
So why are flies so annoying? The answer is simple according to Foster-moisture.
When it's hot and dry, flies are looking for moisture and us sweaty humans are the perfect target.
"During the summer months, the environment may not be providing the moisture they need, but they're attracted to the perspiration on a human so that's why we attract them. We're the things walking around covered in moisture."
Foster said 80 per cent of his clientele are regulars who get their houses treated for insects whether it's a bad season or not.
"It increases when the situation is dire, when fly populations increase we'll get more people calling, but they might get their houses sprayed every 2-3 years, it just depends on the kind of season we're having."
As annoying as they might be, flies hate being out in the heat, with Foster saying the only species silly enough to roam in the blazing sunshine were humans.
"Human beings are the only ones dumb enough to move about in the heat of the day because we've got jobs to do. Animals find a shady spot and do as little as possible and the fly is included in that."
To prevent flies in the home Foster had a few tips to help Hawke's Bay residents keep them at bay during the warmer months, all with one common factor, which was hygiene.
1. Limit moisture in the house
2. Empty household rubbish bins regularly
3. Wipe down surfaces and benches
4. Keep food areas tidy
