HI
This is the last post on this now, as I think i finally know the problem
some drains were moved outside my semi to enable an extension to be built
the drains were not sealed and thre are cavities under the extension which have rats in them, somehow the area has opeened up such that they can get into an internal wall in the house
i can either put conrete in the internal wall, or can pump it up a disused branch of a drain
which is best or what should i do , please !!