How to Get Rid of Rats in Perth

What species are in your roof

Three rodent species cause most calls in Perth's northern suburbs. The Black Rat (Rattus rattus) is the common roof-void climber. It has a pointed head, thin ears and a scaly tail longer than its body. Colour ranges from charcoal grey to light brown above with a cream belly. Body length is around 165 to 205 millimetres and weight 95 to 340 grams.

The Norway Rat (Rattus norvegicus) is larger and ground-based. It has a blunt muzzle, medium ears and a scaly tail shorter than its body. Colouring is grey-brown with a shaggy coat. Body length reaches 180 to 255 millimetres and weight 200 to 480 grams. Norway rats shelter under bushes, in sewers and other urban sites, or construct deep burrow systems.

A rat in a gap between bricks in a wall — A rat in a gap in a brick wall. Gaps like this are how rats get into a house.

Signs you have rodents in your roof or sub-floor

Scratching, scurrying or gnawing in the ceiling, usually from dusk. Black rats are active on the roof structures and inside wall cavities. Norway rats shelter in sewers and construct deep burrow systems.

Droppings are the clearest sign. Black rat droppings are pointed, around 12 millimetres long. Norway rat droppings are blunt and larger, up to 20 millimetres. Look in the roof void, garage, pantry, under sinks and along fence lines.

Gnaw marks appear on cables, sarking, pet-food bags and fruit on trees. Grease rubs form along walls and beams where rats run the same route each night. A pet suddenly fixated on one corner of the kitchen or ceiling often signals an active run above.

Why rodents move into Perth homes in winter

Perth's May to August rains push rats and mice out of bush margins and garden beds toward roof voids and garages. Warmth and water draw them in. A dripping tap, an open compost bin, fallen citrus or a bird feeder left out overnight keeps them there longer than the gap in the eaves does.

Black rats breed quickly with up to six litters per year and five to ten young per litter, weaned in 20 days. A small infestation can become established quickly. The sooner you seal entry points and bait the runs, the sooner the roof goes quiet.

What you can do before calling a professional

Stop the source. Remove pet food bowls overnight. Pick up fallen fruit and close the compost bin lid or convert to a sealed bin. Fix dripping taps and cover rainwater tank openings with 1 millimetre mesh. Store bird seed and pet food in airtight containers, not paper bags.

Clear harbourage. Tidy the roof void of cardboard, old cloth and stored items. Move firewood piles 40 centimetres off the ground. Trim tree branches away from the roof line. Remove thick vegetation against the house wall.

Find the gaps. Walk the perimeter and the roof line (from safe ground). Look for gaps at gutter joints, eave gaps, roof penetrations, sub-floor vents and garage door seals. A black rat needs only a gap about the size of a 20-cent coin; a mouse gets through a gap the width of a pen. Note the gaps and leave them unsealed for now so a professional can map and treat the active runs.

Check product labels. Supermarket baits and traps are available. Always read and follow the label carefully. It is illegal to apply pesticides in a manner that is not indicated on the label.

What not to do when you find rodents

Secure baits in locked, anchored stations. If you have already sprayed with a supermarket bomb or placed uncovered baits, call a professional to assess the run before you treat it yourself. A second treatment in the same area can create safety hazards and waste money.

Remove any old supermarket baits before a professional arrives so they can read the runs and avoid doubling up on treated areas. Rodent infestations often occur alongside other pests; read our guide on how to get rid of German cockroaches or check the general pest control Perth page if you spot other signs.

When to call a professional for rodent management

If you hear ongoing noise or cannot safely access the roof void, call a professional. We identify the species, inspect the roof void where safe, the sub-floor, garage and perimeter, and map every entry gap. We place tamper-resistant stations with registered rodenticide blocks on the external runs and in the roof void. Inside the living space where pets or kids are present, we use covered snap traps to avoid secondary poisoning risk. Most domestic jobs settle within two to three weeks.

Work is carried out by, or under the direct supervision of, a technician holding a WA pest management technician's licence (Health (Pesticides) Regulations 2011). Our process is identify, map, station, seal, and follow up. A follow-up visit checks consumption, repositions stations along the runs and confirms the house has gone quiet. We also give you a written sealing plan for the gaps we find. Simple seals are done on the day; larger work is quoted.

For rodent management in Perth's northern suburbs, contact us via the rodent control Perth page or text your suburb and what you're seeing to 0468 170 107.

What it costs to get rid of rats in Perth

A rodent program with the initial visit, two tamper-resistant stations and a written proofing plan is typically $220 to $380. A follow-up check is $90 to $140. These are typical ranges for a standard home in Perth's northern suburbs, itemised in writing after we have seen it. See the investment guide for more pest management prices in Perth.

Additional stations, roof or sub-floor access and sealing work are quoted separately. No deposit, seven-day payment terms.

What you get from a professional treatment

You receive a treatment report with the species identified, an entry-point audit with photos, every station and trap numbered on a plan, the product and rate used, and a prevention plan split into what we did and what is yours to fix. The treatment record stays on file and is yours on request. It lists the active constituent, the areas treated and the re-entry period.

Rodent baiting carries a three-month re-treatment promise, terms at djpest.com.au/warranty. If rodent activity returns inside the baited areas within three months, we return at no charge. Stations remain ours and are collected when the program ends unless you keep them on a check schedule.

Frequently asked

How do I tell if I have rats or mice?

Droppings are the fastest tell. Gnaw holes confirm it: rats make holes the size of a 50-cent coin, mice make smaller holes.

Are rats and possums different problems?

Possums (Common Brushtail Possums, Trichosurus vulpecula) are marsupials, not rodents. Rats have a distinctive pair of chisel-shaped front incisors with hard yellow enamel. Possums are nocturnal and retreat to hollow logs or trees during the day. Possums are a protected species in Australia. If you hear slow thumping or see larger, fluffier animals, contact a possum-relocation specialist instead.

What is a rat catcher and do I need one?

A licensed technician must be registered with the Department of Health and hold a WA pest management technician's licence. We are a WA Department of Health registered pest management business (registration PMB 3000) and work is carried out by, or under the direct supervision of, a technician holding a WA pest management technician's licence. You need a registered, licensed professional.

How long until the rats are gone?

Most domestic jobs settle within two to three weeks. Rats are neophobic: they avoid new objects in their territory for several days, so a station that looks untouched at day five is normal, not a failure. Mice usually feed within a day or two. The follow-up visit checks consumption and repositions stations along the runs.

Will they come back after treatment?

Almost every re-infestation is an unsealed entry point. We map every gap we find and give you a sealing plan. Do the simple seals and the roof stays quiet. Rodent baiting carries a three-month re-treatment promise, terms at djpest.com.au/warranty. Pests can re-enter from next door, so neighbours' gaps matter too.

Is baiting a risk to my pets and kids?

Inside the house where pets or kids are present, we prefer snap traps in covered boxes to avoid a pet catching a poisoned rodent. Every placement is listed on your report and we brief you on what to watch for.

Do you go into the roof void?

Yes, where the manhole and clearance make it safe. Most northern-suburbs rat activity is black rats in the roof, entering at gutter joints, eave gaps and unsealed roof penetrations. We inspect the void, place stations or traps there, then seal externally. If the void is packed with storage or has no safe access, we work from the exterior and you remove the clutter.

Sources

More guides on rats and mice

Rodent Control Perth, the full service and the investment
Every guide on rats and mice
Pest management investment ranges in Perth, every service with a typical range
What's my pest?, pick what you saw
All pest guides