I just shut them up last night and didn't check they were in there first (as I almost always do because one is always escaping). Went down this morning to let them out and there they were in the run just looking at me!!!
They have got a small fully enclosed run on the house which opens up to a larger fenced in area, they have full access to the larger area - the enclosed run is there as it forms part of the boundary. Anyway the door on the enclosed run had become closed (not totally - they got out of it yesterday morning so I assumed it was fine) so they hadn't gone back in.
What a night to be out in the cold on!
One of them was straight into the house when I opened it to lay.