Rats, Cats and Carpenter Ants

A phone call from a prior customer had me scratching my head.

They informed me that they were certain that they could hear ‘scratching / rustling sounds’ in the wall that divided their kitchen and living room. They also said that cracks had appeared on the surface of the wall but had no idea how long they had been there.

A visit revealed that the wall in question was a stud wall so a hollow wall with a cavity of around 80mm. There were cracks for sure but I could not hear any noise coming from the cavity. My first thoughts were that there was a wasp nest behind the plasterboard.

The only course of action was to cut an inspection hole with no guarantees about how big this job would get. Having no idea of what was about to be revealed a hole was cut approx 200mmx 400mm. The cavity was stuffed solid with sawdust known as frass with the bottom 200mm at ground level having what looked like a rat’s nest.

The property concerned was well kept and tidy. A cleaner also came in once a week. This was no neglected unkempt home. The frass was hoovered out, it filled about 1/4 of a wheelie bin and then the redundant rats nest was found at the bottom of the cavity.  

I remember seeing this before many years ago in an outbuilding in a boat yard that led me to the conclusion that it was an historic carpenter ant nest and an historic rats nest.Carpenter ants are not that common, and you will not find them in modern dry and relatively warm buildings and homes. They prefer damp environments.

 It transpired that this building was once a stable, presumably this would have been a damp enough environment to attract carpenter ants. The rat I guess was just an opportunist who found their way into the cavity probably via an entrance hole in the brickwork. Rats will colonize the cavity of a house to make their nests.

It is important to block any old holes that once had a pipe running through the brickwork to the outside as this is a perfect entrance and exit for these rodents. Rats will climb an exterior wall to get to an entrance hole so a 1st floor bathroom which has an old entrance hole for pipework no longer required can be a way in for them. 

A cat currently resides at the house so any future rat seeking a new home here will have to go elsewhere.