The overwhelming majority of insects and spiders you find around an Adelaide home are harmless, and a fair few are actively useful. But a short list can genuinely hurt you, and almost all of them share a preference: undisturbed clutter, close to the house, where nobody looks.

Cleaning up is the single most effective thing a homeowner can do. The trick is to clean strategically rather than just thoroughly.

Know the short list first

In and around Adelaide, the ones worth respecting are:

• Redback spiders. Native, extremely common, and fond of dry sheltered spots — under outdoor furniture, inside letterboxes, in the folds of a tarp, behind the wheelie bin, in the corners of a shed. Bites are painful and occasionally need medical attention. Antivenom has been available since the 1950s and there have been no confirmed deaths in Australia since.
• European wasps. Introduced, established in South Australia, and much more aggressive than a bee when disturbed. They nest in ground cavities, wall voids and retaining walls, and unlike bees they scavenge meat and sweet drinks, which is why they show up at barbecues. They can sting repeatedly.
• Bees. Not aggressive, but a swarm that establishes in a wall cavity or chimney becomes a structural problem as well as a sting risk.

Worth mentioning what is not on the list: white-tailed spiders. Their reputation for causing flesh-eating ulcers does not hold up — a study that followed up 130 confirmed white-tail bites found no necrotic ulcers at all. Painful, yes. Flesh-eating, no. Huntsman spiders are likewise alarming and essentially harmless.

Clean the places that actually matter

Rather than a general tidy, target harbourage — the sheltered, undisturbed voids where these species sit out the day:

• Under and behind outdoor furniture, pot plants and the barbecue
• Inside the letterbox, meter box and any wall-mounted fittings
• Stacked timber, bricks, pavers and tiles left over from a project
• Shed and garage corners, particularly at floor level and behind stored boxes
• Children’s play equipment, trampoline frames and sandpit covers
• Folded tarps, shade sails, hoses and anything else stored in a coil

Wear gloves and shake things out rather than reaching in blind. If you find a redback and a web with a papery egg sac, remove the sac too — each one can hold dozens of spiderlings.

Then take away the conditions

Once the clutter is gone, remove what supports the food chain. Outdoor lighting draws in the moths and beetles that spiders feed on, so switching to warm-toned or motion-activated lights near doors reduces the insect traffic that makes your veranda attractive in the first place. Fixing leaks, clearing gutters and emptying anything holding water cuts down the moisture that most insects need.

Keep bins closed and rinsed, and pick up fallen fruit — both are magnets for wasps in late summer and autumn.

Where to stop and call someone

Two situations are worth handing over rather than tackling yourself. The first is a wasp or bee nest: do not attempt to treat, block or flood a nest, and do not spray the entrance. Disturbing one provokes a defensive response from the whole colony, and nests in wall cavities in particular need to be dealt with properly. The second is any infestation you cannot find the source of — repeated spider sightings inside usually mean there is harbourage somewhere you have not located.

Not sure what you’re dealing with?

Correct identification changes the treatment completely, and guessing wrong wastes both time and money. If you’d like a professional set of eyes on the problem, request a quote or call us on 08 7095 6992 and describe what you’ve seen.