Intense heat during summer can often bring with it an increase in unwanted visitors — flies and maggots.
So why do they turn up with the heat, and are they problematic beyond just being annoying?
We spoke to experts to answer these questions and find out the best ways to minimise flies in our homes.
Why are there more flies when it's hot?
Flies are cold-blooded creatures, so when it's hot, entomologists say "their bodies get hot, and they get more active".
Higher temperatures can speed up the time it takes a fly to mature — to only a week or two, instead of the usual three or four.
Dan Bickel, an entomologist from the Australian Museum in Sydney/Gadigal lands, says people tend to forget flies are around until a big heatwave.
"They come en masse and it seems like overnight, they're there — but they can leave just as quickly," Dr Bickel said.
"Air masses move, and they carry all sorts of flying insects with them."
Can flies make us sick?
There are 30,000 different fly species, according to Dr Bryan Lessard, an entomologist and science communicator from Canberra/Ngunnawal.
"It's only a handful, like the bush fly and some horse flies, that are annoying and give the rest a bad reputation," says Dr Lessard, who is also known as "The Fly Guy".
He says houseflies and blowflies also get a bad rap because of their potential to transfer pathogens.
"Female blowflies are really good at finding rotten meat to lay their eggs in," he says.
"If they land in something gross and then they come and land on our sausage sandwich, they could mechanically transfer some of those bacteria and viruses."
James Plant, the director of environmental health at the Sunshine Coast Public Health Unit on Kabi Kabi lands, says flies are more of a "public health nuisance than a public health risk".
"But there is that cohort of people that will get a skin infection [from black fly bites] or a gastrointestinal illness as a result of flies," he says.
"With any fly, there's always that risk of them sort of landing on food and contaminating surfaces."
Black flies, also known as sandflies or buffalo gnats, are small flies whose bite can cause swelling, bleeding, pain and itching.
"The preventions are similar to mosquitoes," Mr Plant says.
"That's using an appropriate insect repellent such as DEET, and wearing light-coloured, loose-fitting clothing and making sure fly screens are in good condition."
How to prevent flies and maggots in our homes
When it comes to avoiding the potential for gastrointestinal illness, preventing flies from being around waste, food and kitchen surfaces is key.
"You can be very fastidious about cleaning and prepping raw foods and cooking them and then a fly will come and land on your raw [food], or your chopping board," Mr Plant says.
"And before you know it, everybody's got a bit of salmonella."
He recommends the following steps:
- Using fly screens wherever possible
- Keeping food covered
- Removing waste and fly breeding material regularly
"[Take] out your kitchen waste regularly so it doesn't get too stinky to attract the flies inside," Dr Lessard says.
This is particularly important if you want to avoid a sudden infestation of maggots in your home.
It can take between eight and 24 hours for a blowfly or housefly's eggs to hatch into the tiny white creatures.
Dr Lessard says flies play an important role in the ecosystem and are prolific pollinators, so he discourages killing them.
"Like many people, I hated flies growing up, I thought we could just nuke them and get rid of them, but that would be really scary," he says.
"We definitely want to shift our mindset from killing insects to how do we actually encourage them to survive and thrive."
"Most of the time they're just annoying, so my advice is just to open up the door and shoo the fly out."
How to reduce flies and maggots outdoors
Having food outside on picnic rugs or outdoor tables presents a different challenge.
Our experts recommend always keeping food covered and removing any waste or rubbish that could attract flies to the area.
"Put your garbage bins and compost away from the house," Dr Lessard says.
He recommends against the use of bug "zappers" or popular outdoor fly traps.
"Every time I see one of those baited pheromone traps, I look inside, and I see a lot of flies that aren't necessarily pests," he says.
"One of the best solutions outside [on a covered patio] is just to put your fan on, this will blow the flies and mosquitoes away."
He also suggests planting more native plants in your garden that flower.
"So, you'll bring in spiders and other insects that actually help control those more nuisance fly species in the backyard," he says.
