That 3am scratching above the bedroom is almost always roof rats. Here's how they got in, why bait blocks alone won't fix it, and what a real treatment looks like.
What's actually up there
In Toowoomba it's almost always Rattus rattus — the black or roof rat. They're agile climbers, prefer to nest above ground level, and find a Toowoomba roof void almost perfect: warm, dry, dark, and connected to the entire neighbourhood by overhanging branches and power lines.
Less commonly you'll get bush rats (in semi-rural Highfields or Crows Nest) or the larger brown rat (Rattus norvegicus), which prefers ground level and is more common around chook pens and compost bins.
How they got in
A roof rat can squeeze through a gap the diameter of a 20-cent coin. The usual entry points are:
Gable vents without mesh, or with rusted-out mesh.
Gaps where the roof sheets meet the bargeboard or fascia.
Eave linings that have lifted or rotted.
Around penetrations for solar conduits, evaporative cooler ducting and TV antennas.
Overhanging trees — they don't need an entry on your roof if they can run along a branch onto a neighbour's and across.
Why bait blocks alone don't fix it
Tossing a few bait blocks in the roof void is a common DIY approach and it usually fails for one of three reasons: the blocks dry out and lose palatability, the rats die in an inaccessible cavity and stink for weeks, or the colony simply replaces the lost individuals from the population next door.
A real treatment combines secured external bait stations (so the colony source is dealt with at the property line), targeted internal placements where safe, and most importantly — sealing the entry points so the next group can't move in.
The smell problem
A dead rat in a cavity can smell for 1–3 weeks depending on conditions. There's no spray that masks it effectively — the only real fix is to locate and remove the body, which sometimes means cutting a small access hole in a ceiling or eave lining.
This is one reason a properly designed program tries to do the lethal work outside the building envelope wherever possible.
Pet and child safety
Second-generation anticoagulant baits are highly toxic to dogs and cats if they eat the bait directly, and a small risk to predators that eat poisoned rodents.
A licensed technician uses tamper-resistant bait stations, places them where pets can't access, and rotates active ingredients to avoid resistance. We never leave loose bait blocks.
How long until it's quiet again?
For an average roof rat infestation in a Toowoomba home, we expect noticeable reduction within 5–7 days and complete silence within 2–3 weeks. The exclusion work (sealing entry points) is what stops it coming back next autumn.
FAQs
Are roof rats dangerous?
They carry leptospirosis, salmonella and a handful of other pathogens, and they chew electrical cables — roof rat damage is a recognised cause of house fires. They're worth dealing with quickly.
Will a cat solve the problem?
Almost never. Cats might catch the occasional opportunistic rat in the yard but they don't access roof voids, and the colony breeds faster than a single cat can hunt.