Do you freak out if you spot critters scuttling across the kitchen floor? Before you reach for the insecticide spray, let us tell you about another way ...
A fly against a pink window pane

Flyscreens are a much better solution than fly spray to keep blowflies out (ABC Life: Nathan Nankervis / Flickr: Emma Forsberg)

Lots of us get a bit freaked out when we spot critters scuttling across the kitchen floor and, instinctively, we reach for the insecticide spray to kill.

But there are ways we can deal with bugs without resorting to chemicals, and the uncomfortable truth is there are some creepy crawlies we’re better off keeping around.

Tanya Latty, an entomologist at the School of Life and Environmental Sciences at the University of Sydney, wants us to stop and think before we try to slay anything we find in our homes. “I’m not sure where it originates, this idea that your house is supposed to be sterile and your garden should have just flowers and no insects,” Dr Latty says. “It’s not achievable for one thing, but it also sets up this idea that as soon as you see an ant or a cockroach in your kitchen you have to nuke the place.”

Dr Latty and Bryan Lessard, aka Bry The Fly Guy from the CSIRO, share their tips to help you keep bugs at bay.

A picture of a dead cockroach

The cockroaches you find are seldom Australian native cockroaches. They’re most likely to be introduced pests like German cockroaches or American cockroaches (pictured).

Bug are gross … or are they?

Are cockroaches, ants and flies wandering about your home actually dangerous to our health? Not really, says Dr Latty and Dr Lessard.

“The main risk for things like cockroaches is the fact that bacteria can stick to their feet, so if a cockroach runs across some raw chicken on the bench and then runs across your salad, then it can move the bacteria from the chicken to the salad,” she says.

Some people can be allergic to cockroach exoskeletons and their poop, but that will only be a problem if you have large numbers of them. “Having huge numbers of cockroaches in your kitchen is probably not great,” Dr Latty says. “But having one cockroach doesn’t mean you’re going to die of the plague. You get way more [bacteria or pathogens] from another mammal than any insect.”

Dr Lessard says apart from mosquitoes, which are a type of fly, even the biggest blowfly isn’t very likely to bring you any harm.

Ants also tend to not be a real health risk, unless you’re unlucky enough to have a fire ant nest invading your dining space. The little black house ant, sometimes called sugar ants, aren’t dangerous.

Dr Latty says our sense of risk with insects, even when it comes to venomous spiders, tends to be “totally warped”. “You’re literally more likely to be hit by lightning than to die of a spider bite,” she says.

A picture of a huntsman spider on a fridge

Huntsman spiders are your friends. These Australian spiders eat cockroaches, flies, ants and other spiders, so it’s a good thing to have them around.

Why are there insects in my house?

It’s not just cockroaches, ants and flies hanging out in your pad, you’ve probably got about 100 different species of insects living with you, most of which you don’t even notice. Bugs move in with us for the food, water and warmth our homes provide. So if you’re trying to evict unwanted roomies, you need to stop them having access to the things they want.

Dr Latty and Dr Lessard say preventing unwanted insects from getting inside in the first place is better than launching chemical warfare.

Excerpt published with permission from ABC Life.


  1. Does the active ingredient in cockroach baits (eg Indoxacarb) remain in the body of a cockroach and poison the ants that eat the dead cockroach? I notice that as the summer goes on, dead cockroaches take longer and longer to be removed by the ants,

  2. About 25 years ago I was driving up the M5 Freeway from Campbelltown going towards Liverpool .
    The sun was in my eyes so I put the sun visor down.
    The biggest huntsman spider I have ever seen flopped down the inside of my shirt and instantly got tangled up in the hair on my chest.
    I was aware they are not supposed to be venomous so the only danger I considered myself to be in was the four lanes of traffic either side of me full of vehicles all doing 110kph.
    I figured this could turn into a multi vehicle high speed traffic accident, people could be maimed and lives could be lost in the process.
    I had to think cool so I gripped the steering wheel in my right hand and began undoing the bottom button of my shirt, by the time I reached the third button it was obvious to me the spider had seen an exit so I lifted the corner of my shirt and it ran down my leg and disappeared up under the dashboard.
    The hairs on the spider’s legs broke off and acted like itching powder.
    When I got home rather than kill it I left the windows down overnight and the spider made its way out of the car, they have an important job to do in controlling insects.
    It bit my chest when it flopped down inside my shirt.
    That wasn’t painful but an infection set in resulting in a mole growing resembling a new nipple, a surgeon removed that.
    Recently a skin cancer was excised from the same spot.

  3. Yes we have wasps here that eat spiders. Everyone is cared what a wasp flies into the house, but noone has been stung in 5 years so can’t be too dangerous. We make sure to put our bin our every night and never have rubbish in the house overnight. This seems to help. Our dog also likes to catch flies! He has an exciting life…

  4. We live in country NSW, notorious for the summer blowfly season. This year I forgot to clear all the small wasp nests around our house that occupy areas eg under the guttering, under the front and back verandah etc. We suddenly realised this summer we saw very few blowflies, and we have cans of unused fly spray, Oh and by the way, we didn’t bother the wasps and they didn’t bother us!

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