Signs You Have Rodents in Your Roof (And What to Do About It)

Common Signs of Rodents in Your Roof

Rodent infestations in Sydney roofs are common, particularly in older homes and during cooler months. Here's how to identify if you have unwanted guests overhead.

1. Scratching and Scurrying Sounds

The most common sign is noise, particularly at night when rodents are most active.

• Rats: Fast, light scurrying sounds throughout the night
• Mice: Very light scratching, often sounds like something brushing against surfaces
• Possums: Heavy thumping, mainly at dusk and dawn (protected species - different removal process)

2. Droppings

Rodent droppings are a definitive sign of infestation:

• Rat droppings: 10-15mm, dark, pointed at ends, found in concentrated areas
• Mouse droppings: 3-6mm, dark, pointed, scattered randomly
• Fresh vs old: Fresh droppings are dark and shiny; old ones are dry and grey

Check your roof void (if safely accessible), garage, and behind appliances.

3. Gnaw Marks

Rodents must constantly gnaw to keep their teeth worn down. Look for:

• Chewed edges on stored boxes and materials
• Gnawed timber, particularly around entry points
• Damaged electrical wiring (serious fire risk)
• Chewed PVC pipes

4. Grease Marks (Rub Marks)

Rodents follow the same paths repeatedly, leaving dark grease marks from their oily fur. Look for these along:

• Walls and baseboards
• Around entry holes
• Along pipes and cables

5. Nests and Nesting Materials

Rodents build nests from shredded materials including:

• Insulation (often damaged or displaced)
• Paper and cardboard
• Fabric and soft materials

6. Unusual Pet Behaviour

Dogs and cats often detect rodents before humans. Watch for:

• Pets staring at walls or ceilings
• Scratching at particular areas
• Unusual alertness at night

Rats vs Possums: Key Differences

This distinction is important because possums are protected wildlife in NSW and require different handling. Possum removal must be done by a licensed operator — it's illegal to harm, trap, or relocate possums without proper authorisation.

Characteristic	Rats	Possums
Sound	Light scurrying, gnawing	Heavy thumping, hissing
Activity Time	Throughout night	Dusk and dawn mainly
Droppings	10-15mm, pointed	20-30mm, rounded
Urine Smell	Strong ammonia	Less pungent
Damage	Gnawing on everything	Minimal damage
Legal Status	Pest (can be killed)	Protected wildlife

Health Risks of Roof Rodents

Rodent infestations pose genuine health risks that shouldn't be ignored:

Disease Transmission

• Leptospirosis: Spread through contaminated urine
• Salmonella: From droppings contaminating food prep areas
• Hantavirus: Transmitted through dried droppings and urine
• Rat-bite fever: From bites or scratches

Other Hazards

• Fire risk: Gnawed electrical wires cause house fires
• Allergies: Rodent dander and droppings trigger allergic reactions
• Contaminated insulation: May need replacement after heavy infestation

Immediate DIY Steps

While professional rodent control treatment is recommended, you can take immediate action:

1. Identify Entry Points

Carefully inspect your property for gaps:

• Check where pipes and cables enter the building
• Inspect eaves and fascia boards
• Look for gaps around roof tiles
• Examine vent covers

2. Remove Food Sources

• Store all food in sealed containers
• Don't leave pet food out overnight
• Secure garbage bins
• Clean up fallen fruit from trees

3. Reduce Habitat

• Trim tree branches near the roof (2m clearance recommended)
• Clear garden debris and woodpiles
• Remove dense vegetation against walls

Professional Solutions

An EPA-licensed pest controller will typically:

Inspection

• Identify rodent species and activity level
• Locate entry points and harbourage areas
• Assess extent of damage

Treatment Options

• Baiting programs: Secure bait stations in roof void and external areas
• Trapping: For sensitive areas or quick knockdown
• Exclusion work: Sealing entry points to prevent re-entry

Expected Timeline

• Initial knockdown: 1-2 weeks
• Complete elimination: 2-4 weeks
• Follow-up visits: 2-3 visits over 4-6 weeks

Preventing Future Infestations

After treatment, maintain a rodent-free home:

• Schedule annual inspections with a licensed pest controller
• Maintain tree trimming (quarterly)
• Regular exterior inspections for new entry points
• Keep garage and storage areas tidy
• Continue food hygiene practices