Thanks Kva,just wondered as I saw something 'strange' outside last night....we have aircraft flying over here and thought it was one. However the manoeuvre it made was no airliner.... Too quick, too abrupt and dropped and rose which couldn't be done by an airplane. I conclude it was a drone but it did look like it had windows on it. Oh well...at least I know it's possible for it to have been a drone thank you.