1. Narrow Down the Location:
* Listen carefully: Try to pinpoint the exact spot where the sound seems loudest. Does it seem to move around or stay in one place?
* Visual inspection: Check the area where you hear the noise during the day. Are there any visible signs of damage like small holes, loose wood, or wood shavings?
* Use tools: If possible, tap on different sections of the wall or floorboard to see if the sound changes or resonates. This might help identify a hollow area.
2. Consider Other Possibilities:
* Insects: Certain insects, like beetles or carpenter ants, can create scratching sounds as they burrow into wood. They often leave sawdust or small holes.
* Expanding/Contracting Wood: Changes in temperature and humidity can cause wood to expand and contract, which can create creaking or scratching noises.
* Loose Objects: Something as simple as a loose picture frame or a piece of furniture rubbing against the wall could be the culprit.
* Pipes: If the scratching sound is near plumbing, it could be caused by pipes expanding or contracting due to water pressure or temperature changes.
3. Eliminate the Cats:
* Observe their behavior: Do your cats exhibit any unusual behaviors during the night, like increased activity or scratching at walls?
* Try temporary deterrents: Place cat toys or a scratching post near the area to see if it redirects their attention.
* Consider a night camera: A pet camera can help you monitor the area and see if any of your cats are actually responsible for the noise.
4. Call in the Professionals:
* Pest control: If you suspect insects, a pest control professional can inspect the area and identify the cause of the scratching.
* Carpenter: If you think the sound might be due to structural issues, a carpenter can examine the affected area and recommend solutions.
Remember:
* Be patient: It might take some time to isolate the source of the scratching.
* Keep a log: Note when you hear the noise, where it seems to be coming from, and any other relevant information. This will help you track the problem.
Good luck with your investigation!