I have been hearing noises in my chimney breast for the last couple of mornings. It starts about 8.45am and continues on and off for a couple of hours, it's like a scratching/moving around noise but then goes quite and there is no movement for the rest of the day and evening. There is no longer a fire in the chimney and the opening has been plastered up so we are not able to take a look without ruining the wall. Has anyone any ideas what it could be and if so how to get rid of it ? Many thanks