Rat Infestation: 12 Signs, Risks and What to Do Next

One rat sighting does not always reveal the scale of a problem. Rats are cautious, mainly active after dark and capable of travelling through drains, wall voids, gardens and adjoining properties. The useful question is not simply “did I see a rat?” but “what other evidence shows where it is feeding, nesting or entering?”

The 12 most common signs of a rat infestation

1. Fresh droppings: dark, spindle-shaped droppings around food stores, bins, cupboards or travel routes.
2. Scratching noises: movement in walls, ceilings, lofts or under floors, especially at night.
3. Gnaw marks: damage to food packaging, timber, plastic pipes or electrical cables.
4. Greasy rub marks: dark smears where rats repeatedly travel beside walls or pipes.
5. Footprints and tail marks: visible in dusty areas, plant rooms and undisturbed corners.
6. Nesting material: shredded paper, fabric or insulation gathered in a sheltered void.
7. Burrows: holes near sheds, decking, compost areas, walls or dense planting.
8. Strong odour: a stale, ammonia-like smell that becomes stronger near activity.
9. Pet behaviour: unusual focus on a cupboard, wall, floor void or appliance.
10. Damaged food: scattered food, pierced packets or contamination in cupboards.
11. Daytime sightings: sometimes a sign of competition, disturbance or a larger population.
12. Dead or live rats: direct confirmation, although the entry route may still be elsewhere.

Where rats commonly hide in London properties

Typical harbourage includes subfloors, loft insulation, boxed-in pipework, basement storage, commercial bin areas, drains, overgrown gardens and spaces below decking. In terraced buildings and converted flats, activity may cross party walls or shared service routes, so the room where a noise is heard is not necessarily the point of entry.

Rat droppings: what they look like

Rat droppings are usually larger than mouse droppings and often have tapered or blunt ends. Fresh droppings tend to look dark and slightly glossy; older material becomes dull and dry. Do not sweep or vacuum suspected droppings while dry. Ventilate the area, keep children and pets away, and use appropriate protective and cleaning precautions.

If identification is uncertain, compare the evidence in our rat vs mouse droppings guide.

Why rats are a property and hygiene risk

Rats can contaminate food-contact areas with urine, droppings and material carried on their bodies. They may also damage stored goods, insulation, doors, pipework and wiring. The risk is greater in kitchens, food businesses, blocks with shared waste areas and properties where activity reaches occupied rooms.

If anyone is bitten, or becomes unwell after contact with rodent-contaminated material, seek medical advice and explain the possible exposure.

What to do when you find signs of rats

1. Photograph the evidence and note when and where it appeared.
2. Place food, pet food and bird seed in sealed, robust containers.
3. Remove accessible waste and clean spills without dispersing contaminated dust.
4. Do not immediately seal an active entry point if this could trap rats inside.
5. Arrange an inspection when there are repeated signs, indoor activity or uncertainty about drains and structural routes.

Why DIY control often fails

A trap or bait may remove an individual rat but leave the access route, food source and harbourage unchanged. Poorly positioned control can also make rats avoid new objects, move activity deeper into a structure or create an inaccessible carcass. A successful programme combines identification, targeted control, monitoring, sanitation and proofing at the correct stage.

How professional rat control works

A technician should inspect the affected rooms and likely external routes, distinguish rats from mice, assess risks to people and pets, and choose controls suitable for the property. Follow-up matters: activity should be monitored, findings recorded and proofing recommendations completed after control has been achieved.

How to prevent rats returning

• Keep bins closed and avoid loose waste beside the property.
• Clear food spillage beneath bird feeders.
• Repair damaged vents, doors, drains and service penetrations.
• Reduce dense clutter and inaccessible harbourage.
• Store food and animal feed off the floor.
• Investigate recurring drain-related activity rather than repeatedly treating symptoms.

Frequently asked questions