Squirrel's are a pest but do they cause condensation? Building's technical editor is not too sure and is happy to open the question to the floor

We get some weird calls here at the tech desk at building.

The latest one was from some guy ringing up on behalf of his neighbour, who was presumably too shy to ring us directly.

The problem was this unnamed person has never had any condensation in his/her roofspace since the house was built in 1975. Then suddenly, out of the blue they discover condensation in the roof space. Did we know the answer?

The only thing we have to go on is some new guttering has been recently installed, and that some squirrels have moved into the roof space. Our man seems to think the squirrels must be at fault. I say it is very difficult to say what the problem is without seeing it, and on the basis of very limited information. However I suggest the possibility that a new fascia board for the guttering could have blocked up eaves level ventilation holes. I suggest the squirrels are a red herring, so to speak.

We discuss this problem after the call and another possibility is raised. Perhaps the squirrels are guilty after all. They might be nesting over the ventilation holes, but another possibility is the squirrels are relieving themselves inside the roof space and raising moisture levels, thus causing condensation.

Has anyone out there ever experienced squirrels causing excessive condensation levels, or any other strange animal related building problem so we can speak with greater authority and knowledge next time someone calls us up?