Homeowners' first instinct may be to pick up the phone and call the fumigators.

But many people are often disappointed to find an army of eight-legged fiends have returned to the battle scene within a few weeks of spraying with insecticide. 

Sam Yehia, owner of Sydney Best Pest Control, says that this disappointment is usually due to a lack of information provided to customers.

"Customer service is important. Some technicians turn up to [a customer's] door and don't explain to the customer what they are going to do... and afterwards the expectations. It's pest control, not pest eradication," Mr Yehia said.

"If you can't spray a spider, you can't kill it. When it come to funnel webs, wolf spiders, or mouse spiders - ground spiders - you won't ever completely get rid of them with just spraying because they roam around hunting."

Macquarie University post-doctoral researcher Lizzie Lowe says spraying gardens with broad spectrum insecticide destroys the eco-system, allowing only the "hardiest" of pests to flourish with unlimited resources.

"People may want to eradicate everything in the backyard, but you shouldn't actually want every insect in your garden dead. You want to have the good guys to help control the bad guys... so you don't have these massive outbreaks of creatures," Dr Lowe said.

Black house spiders and cockroaches are the most common critters to return after fumigation, according to Dr Lowe. 

Both Mr Yehia and Dr Lowe agree that, generally, spiders do more good than harm in the backyard.

"Spiders eat flies, moths and flying insects that could bother you in your garden, or juvenile forms of these bugs like caterpillars who are eating your plants," Dr Lowe said.

"I think a lot of people think that every spider is out to get them. In Australia, we have over 8000 species of spider and only two that will kill you, and they haven't killed anyone in 40 years.

"A lot of people who report spider bites are often misdiagnosed and haven't actually seen a spider. In the case of the white-tail spider there is no evidence that they have a flesh-eating venom; usually these wounds are bad because of bacterium that comes in afterwards."

Mr Yehia recommends dealing with spiders without upsetting their natural habitat by cleaning the gutters, and changing white outdoor lights to fluorescent lights to avoid attracting spider-food like moths and mosquitoes.

To keep redback spiders away from children, he suggests putting their toys in a plastic bucket of water overnight. Homing two chickens in the backyard to hunt and eat ground spiders, like funnel webs, also prevents against infestations without disrupting the eco-system.

If you are going to spray for spiders in your home, he says to "avoid spraying bushes or the fence line to avoid [unnecessarily] harming the spider life".

When it comes to redback spiders, though, Mr Yehia says it's important to spray for them in newly built homes, as they usually "come from brick work".

"If you let them build up too much, they can go into the weep holes of the house, up into the roof, and back into the house," he said.

"The most important thing is that, whoever does the pest control, that the roof gets dusted - most insects, whether they are cockroaches or spiders live in the roof."