Click to see the big version!
We had the fire pit going on the logear, which is what I reckon scared him in through the french windows. Thankgod 2 minutes with a fishing net and a big bit of cardboard was all that took to get him back out again.
After a bit of investigation on google, we thinks he's either a grey or brown long eared bat.
Check these links out for a bit more info.
http://www.worlddeer.org/britishbats/clebat.html
http://www.worlddeer.org/britishbats/glong.html
My money's on the grey version, which would be cool as they're the rarer of the two breeds and only populate the south west. Either way, we're sending the photo to the wiltshire wildlife trust monday to see if they can tell us.
