It was curled up on the flagstone outside tonight, its body was cold (I thought it was dead) but I brought it in to have a look (dark by the house). It did recover somewhat so I snipped a branch off the forsythia - the shrub nearest to where I found it and rested it on the branch. It is about 1½ to 2 inches long and quite chubby and round.
Any suggestions what it is please?
Paul.