Possibly Vermin?
It is not unusual for an older home to have rats or mice nesting within the roof and walls. So although at first, this was the top of their list of suspicions, vermin usually make a unique ticking sound, so the family was quite sure it was not a rat or mouse nest, and they could cross that off their list.

Possibly Vermin
If it was, it would have to be a fairly large number of vermin to explain the volume and locations of the noises. They decided they couldn’t be sure unless they got the experts in, even secretly wishing that was it and the mystery would be solved.
How would they deal with this?
Calling The Exterminators
In case the sounds they heard were vermin, the family called in the experts. They helped guide the exterminators so that they could treat the correct areas in the house by listening to the noises.

Calling The Exterminators
The pest-control company treated all the areas where the sounds had been heard and were sure that if it was vermin, their treatment would drive them out. Still, no one really knew what was causing the noise.