Before you start

Keep children and pets out of the search area. Do not reach into a dark cavity, remove power points, enter an unsafe roof space or disturb suspected asbestos. If you find the carcass, follow appropriate protective, cleaning and disposal guidance.

1. Rule out other odour sources

Check bins, food, drains, appliances, damp materials and pet accidents first. A dead rodent smell is often described as strong, sweet and putrid, but smell descriptions are subjective. A persistent drain, gas or electrical smell needs the relevant licensed professional.

2. Map the smell room by room

Close internal doors for a short period, then compare rooms. Note where the smell is strongest and whether it changes when air conditioning, exhaust fans or windows are used. Repeat at a similar time the next day; wall and roof temperatures can change airflow.

3. Check likely accessible locations

  • Behind and beneath refrigerators, ovens and other appliances
  • Inside the back of cupboards and under sinks
  • Roof and subfloor areas that are safely accessible
  • Garages, storerooms and meter-box surrounds
  • Near known bait stations or traps
  • Along previous signs of rodent movement, such as droppings or gnaw marks

4. Inspect cavity exit points

Compare the smell near skirting gaps, pipe penetrations, vents and cupboard voids without placing your face directly against an opening. Do not spray into or dismantle a power point. Remember that air can travel along the cavity, so the strongest opening may not be directly beside the carcass.

5. Look for insect activity

A cluster of blowflies repeatedly appearing near one window, light fitting or section of wall can help narrow the search. Flies are a clue, not proof of an exact location, and ceiling electrical fittings should be left to a qualified person.

6. Decide when to stop

Call a pest technician when the location remains uncertain, the smell followed professional treatment, there are multiple signs of infestation, or access is hazardous. An inspection camera may help where there is an existing safe access point, but unnecessary holes can cost more than waiting for a small inaccessible carcass to decompose.

Once you find the likely area

Read what to do about a dead mouse in a wall, check the health and cleanup precautions, or use our complete dead rodent odour guide.