How to Get Rid of Mice in Perth

What house mice look like

House mice (Mus musculus) are small rodents, reaching up to 10 cm in body length and weighing up to 30 g. They are grey, brown or black. Mice are often confused with young rats or brushtail possums in roof voids. Possums are much larger (up to 55 cm) and nocturnal, retreating to roofs or branches during the day. Mice scurry and leave rice-grain droppings 3 to 6 mm long. See Black rats and Norway rats, the other common roof pests in Perth's northern suburbs.

Close-up of mouse droppings on a surface, showing the small rice-grain shape — Mouse droppings (3 to 6 mm) compared to other rodent sign.

Signs you have mice in Perth homes

Mice are active mostly at night. You may not see them, but the signs are clear.

Droppings in the roof void, garage, pantry, under the sink or along the fence line. Mouse droppings are rice-grain shaped, 3 to 6 mm long.
Scratching, scurrying or gnawing noises in the ceiling, usually from dusk onwards.
Gnaw marks on electrical cables, pet-food bags, sarking (roof lining), fruit trees and the edges of stored cardboard boxes.
Grease rubs: dark smudges along a wall or beam where a mouse runs the same route each night, following the scent trail of previous trips.
A pet suddenly fixated on one corner of the kitchen or ceiling, tracking movement inside the walls.
Small entry holes in skirting boards, around pipes and conduits.

Why mice come inside, and when they peak

Mice come indoors for three reasons: warmth, shelter and food. Perth's May to August rains push rodents out of bush margins and garden beds toward roof voids and garages. Once inside, a dripping tap, an open compost bin, fallen citrus on the ground, a pet bowl left out overnight or spilled seed under a bird feeder keeps them there. A mouse needs only a gap the width of a pen and a small amount of dropped food to settle.

Mice breed quickly, approximately every 20 days.

What you can do yourself (non-chemical)

Preventing mice is simpler than treating them.

Deny them food. Ensure all food is sealed in containers with close-fitting lids. Dispose of food scraps promptly and clean food preparation areas thoroughly. Store pet food in sealed containers and remove pet bowls at night. Pick up fallen fruit from around citrus trees daily. Use airtight containers for bird seed and chicken feed.
Remove shelter. Clear the property of clutter, rubbish, old materials and vegetation close to the building. Regularly clean sheds and storage areas. Store firewood at least 40 cm above the ground. Remove garden waste and disused materials. Do not use open compost; maintain compost bins and do not include meat scraps.
Block access. Inspect the building for potential entry points: gaps around pipes, holes in skirting boards, sub-floor vents, garage door seals and conduit entries. Repair or fit mesh screens to windows and doors. Check and maintain these regularly.
Fix water sources. A dripping tap is a magnet for mice. Repair leaking pipes and cover rainwater tank openings with wire mesh.
Remove supermarket baits. If you have already put down over-the-counter baits, remove them before a professional arrives. Fresh baits work better, and a professional needs to read the runs without interference.

What not to do

Supermarket mouse baits and traps often fail because they target the symptom, not the entry point. Baiting without sealing gaps is like mowing the lawn every week and never fixing the mower blade: the problem returns. Ultrasonic and electromagnetic devices are widely sold but have little to no effect on mice; the US Federal Trade Commission advised over 400 retailers of these risks in 2001.

Already sprayed at home without result? Get it checked. A professional can identify why the baits are not working: wrong species identification, bait placed away from the runs, or entry points still open. Baits applied to label and placed correctly work fast, but sealing is the finish line. See what rodent control costs to understand the investment.

When to call a professional

If droppings appear indoors, if you hear scurrying at night, or if DIY sealing has not stopped the noise within a week, call a professional. Rodent management in Perth starts with species identification. We inspect the roof void where safe, the garage and perimeter, and map every gap we find. Locked, anchored stations with APVMA-registered rodenticide blocks go on the external runs and in the roof void. 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). A follow-up visit checks consumption, repositions stations along the runs and confirms the house has gone quiet. Rodent baiting carries a 3-month re-treatment promise (terms at djpest.com.au/warranty): if rodent activity returns inside the baited areas within that period, we return at no charge.

What it costs

A rodent program with the initial visit, species identification, two tamper-resistant stations, entry-point audit and a written proofing plan typically runs $220 to $380, GST inclusive. A follow-up check is $90 to $140. Additional stations, sealing work and roof or sub-floor access are itemised on the quote. Typical range for a standard home in Perth's northern suburbs; every job is itemised in writing after we have seen it. There is no call-out fee, no deposit and seven-day payment terms. For a more detailed breakdown, see the investment guide for pest control in Perth.

Frequently asked

How do I tell if I have mice or rats?

Mice leave droppings 3 to 6 mm, rice-grain shaped, scurry and gnaw small holes. Rats leave droppings roughly 10 to 20 mm depending on species (roof rats around 12 mm and pointed; Norway rats up to 20 mm and blunt), thump across the roof void and gnaw holes the size of a 50-cent coin. Black rats are climbers; Norway rats are ground and sub-floor animals. Species identification matters because treatment differs. See the rat control guide for comparison.

How long until the mice are gone?

Most domestic jobs settle within two to three weeks. Mice usually feed within a day or two once they accept the station. The follow-up visit checks consumption and repositions stations along the runs.

Is baiting a risk to pets and children?

Every placement is listed on your report and we brief you on what to watch for.

Will mice come back after treatment?

Almost every re-infestation is an unsealed entry point. A mouse gets through a gap the width of a pen. We map every gap we find and give you a sealing plan, do the simple seals on the day, and quote anything larger. Rodent baiting carries a 3-month re-treatment promise (terms at djpest.com.au/warranty).

Do you go into the roof void?

Yes, where the manhole and clearance make it safe. We inspect the void, place stations or traps there, then seal externally.

Can I use a trap instead of bait?

Traps can work. The spring back-break trap is the safest trap for home use. When applied correctly and placed along mouse runs, it may reduce an infestation without rodenticides. Success is slow unless the runs are identified first. Professional placement, mapped and documented, is more reliable than trial-and-error.

Mice vs rats in Perth: what is the difference?

Black rats are climbers; Norway rats are ground and sub-floor animals. Rats reach up to 25 cm body length and are much larger than mice. Mice reach up to 10 cm. Droppings tell the story: mice 3 to 6 mm rice-grain, rats 10 to 20 mm blunt or pointed. Treatment differs by species.

Sources

Text your suburb and what you're seeing to 0468 170 107 for a written price.

More guides on rats and mice

How to Get Rid of Rats in Perth

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