The subsequent liquid release will leave a mark as well as a pungent odour.
Possum or rat in roof.
They normally scurry around both day and night.
The is generally two animals which make noises in your roof.
They can be extremely noisy running and thumping through your ceiling.
If they are nesting on the insulation in the roof this can become damaged through constant urination and will require replacing.
The leave your roof at night and come back before dawn.
The 2nd noise could be rats or mice.
Possums do nest in roofs but are mainly active at night and although they are agile climbers are heavier than rats in their movements.
Possums will only be on your roof regularly for three reasons they are living in your roof they are living on your roof or they are using your roof to get from a to b.
Rats either way if you think there may be possums in the roof then every effort must be made to get them out before you try and deal with rats.
They may eat fruit and other human leftovers but tend to feed on native vegetation and are not found as often as rats are scavenging indoors and or ransacking stored foodstuffs.
Rats and mice constantly move around except when nesting.
Other tell tale signs that a possum is living in your roof can be stains on a ceiling or drip marks down your walls caused by urine.
A possum is a large animal and it has no qualms relieving itself in your roof.
Possums and rats can cause damage in the roof by eating through electrical wires.