Perth’s warm climate means ants are a year-round nuisance for many homes. Residents often report tiny sugar or “ghost” ants marching across benches, or long brown trails winding through the garden. These pests are more than a minor annoyance – they can contaminate food and even damage property. To help, Nest Free Pest Control, your local Perth pest experts, has compiled what Perthers need to know: how to recognize the ants that plague our homes, when they’re most active, simple do-it-yourself tips, and when it’s time to call in the professionals.
- Ghost Ants (Tapinoma melanocephalum): Tiny (about 1.5 mm) with a dark head and pale, almost translucent legs and abdomen. Ghost ants love moisture, so they often nest behind sinks, in wall voids or potted plants. Despite their size, they can bite (slightly) and emit a foul odor when crushed. They readily contaminate food because they forage indoors for sweets and grease. Multiple “ghost ant” nests can appear suddenly in kitchens or bathrooms, especially in warm, humid weather.
Argentine Ants (Linepithema humile): Small (2.6–3.2 mm), uniformly dark brown ants that march in very long trailsagric.wa.gov.au. This invasive species has been in Perth since the 1940s and thrives in suburban gardens. Argentine ants invade homes searching for food and moistureagric.wa.gov.au, and are so aggressive that they displace other ant species. You’ll often find hundreds of them swarming sidewalks, logs, or window sills. If you see long lines of dark ants heading to your patio or bin, think Argentine.
- Coastal Brown (“Big-Headed”) Ants (Pheidole megacephala): Light golden-brown ants known for building enormous outdoor colonies. In Perth they favor sandy soils and can form “super-colonies” that span yards or blocks. Coastal browns dig in lawns, garden beds or under mulch, sometimes undermining pathways. Workers have disproportionately large heads (hence the name). These ants mostly stay outside, but will invade kitchens or sheds for food and water. Spotting many ants around a single soil nest is a sign of coastal browns.
- White-Footed House Ants (Technomyrmex spp.): Dark brown to black ants, 2.5–3 mm long, with distinctly pale(white) leg tips. They do not sting. These ants form massive multi-queen colonies that nest in trees and wall-voids or roof cavities. Indoors, they show up in persistent trails along skirting boards, windows or door frames, often in pursuit of sweet honeydew or kitchen scraps. White-footed ants can be extremely hard to eliminate, since sprays rarely penetrate their hidden nests.
Other occasional invaders in Perth include the large black bulldog (Myrmecia) ants outdoors – dangerous only for their sting – and small pavement or sugar ants near footpaths. However, the four types above are the ones Perthers most often report as household pests.
Summer (Dec–Feb, Peak Season): High heat and demand for water drive ants indoors. “As we get into summer… they get more active,” and ants enter homes to forage. Scorching days send colonies indoors searching for moisture, so you’ll see trails in kitchens and bathrooms. Sugar-loving species – like black sugar ants, coastal browns and Argentine ants – are especially active hunting drinks and desserts. Notably, summer rainstorms often trigger indoor invasions: wet weather floods ants out of the yard, “making it easier for them to get into houses”. Tip: Keep surfaces clean and fix leaks before summer – even a small dribble of water or spoonful of honey can attract hundreds of ants.
Autumn (Mar–May): As temperatures begin to cool, ant colonies focus on growth. Many species expand their nests and forage heavily to build food stores for winter. You may notice more ants around gardens and sheds. White-footed house ants and even bull ants become more visible as colonies strengthen. It’s a good time to bait ants before they hunker down for winter.
Winter (Jun–Aug): Ants don’t disappear in winter; they move indoors. Cooler weather slows their activity, but colonies often retreat into warm wall voids and under floors. Black household ants and the elusive ghost ants can remain active in heated rooms. You might catch an ant scurrying across your bathroom tiles or inside a cupboard. Because ants can continue to breed indoors in winter, an undetected infestation now can mean a much bigger problem in spring.
Spring (Sep–Nov): Many colonies enter breeding/swarming season. Flying winged ants (alates) often appear around windows, lights or in heaps on the ground – a sign of new nests forming. If you see swarms or small soil mounds in your yard, act quickly: it means ant populations are booming, and treating outdoor nests early can prevent an explosion of workers indoors.
- Sanitation & Food Storage: Keep kitchens and patios spotless. Wipe up crumbs and spills immediately and don’t leave dishes out. Store food (including pet food) in airtight containers or the fridge. Ants follow scent trails to food, so eliminating these trails is key. (Even a teaspoon of honey or syrup can sustain a colony.) Cleaning regularly can noticeably reduce ant activity.
- Seal Entry & Remove Moisture: Inspect your home for gaps and cracks (around windows, doors, pipes,foundations) and seal them. Fix dripping taps, leaking hoses and clogged drains – moisture attracts ants. Trim back plants and tree limbs that touch your house to block ant bridges, and move firewood or debris piles away from walls. Reducing moisture and hiding spots in your yard makes your home much less inviting.
- Outdoor Maintenance: Keep mulch and organic debris (leaf litter, compost) away from your home’s perimeter. Water lawns and gardens moderately; overly wet soil attracts ants. If you find ant mounds in the yard, rake them flat and treat with bait around the base rather than trying to flood or dig them out. Consistent habitat management makes DIY efforts more effective.
Overall, home remedies can help control small, isolated ant sightings. For instance, a vinegar-and-water spray or a teaspoon of borax in jelly might give short-term relief. But if the trails return in force or spread, it usually means the colony is still alive.
Sometimes, however, DIY methods aren’t enough. If ant trails keep coming back, or if you suspect a hidden nest inside the house, it’s time to call in the professionals. For example, seeing many ghost ants on a kitchen bench or finding multiple nests of white-footed ants are signs that a colony is established beyond DIY control.
If ants are bugging you, give Nest Free a call. Our friendly local team will inspect your home, explain the treatment plan, and help you reclaim an ant-free home. With Nest Free on your side, you can enjoy your Perth summer (and every season) without unwanted six-legged guests.
