Noises in the ceiling sound bigger than they are, and at two in the morning everything sounds like a rat. Before you buy bait, spend a couple of nights listening. The timing and the type of noise will tell you most of what you need to know, and the answer changes what should be done about it.
Listen for when it happens
- Just after dusk, then again before dawn: almost always a possum leaving to feed and coming home.
- On and off right through the night: rats or mice.
- First light and during the day: birds, usually starlings, sparrows or mynas nesting under the eaves.
Then listen to the sound itself
A brushtail possum is about the size of a cat and sounds like it. You hear heavy, slow thumps across the ceiling, sometimes a run, and now and then a hiss or a rough coughing growl. It tends to use the same path each night.
Rats are lighter and quicker. Expect fast scurrying, short stops, and a steady gnawing or grinding sound, often inside a wall or above the kitchen. Mice are quieter again: a faint scratching, usually low in a wall or behind the oven instead of overhead.
Birds flutter and chirp. If the noise stops when it gets dark, it is not a rodent.
Clues you can check from the ground
You do not need to go into the roof, and please do not. Ceilings are not made to be walked on and old wiring is up there. From the ground you can look for a lifted tile or a broken eave lining, branches within a couple of metres of the roof, and droppings on the path below. Mouse droppings are the size of a grain of rice. Rat droppings are closer to an olive pip. Possum droppings are bigger again, about the length of a thumbnail or more.
Why it matters which one it is
Possums are protected native wildlife in Victoria. They cannot be poisoned or moved to another suburb, and rat bait put out for a noise that turns out to be a possum is both illegal harm to wildlife and a dead animal in your ceiling. The fix for a possum is letting it out through a one-way door and sealing the hole.
Rats and mice are treated with traps, locked bait stations and sealing their entry gaps. Nesting birds are a proofing job once the chicks have gone.
If you still cannot tell after a few nights, write down the times and call us. A roof inspection starts with exactly those notes.