Wow thats weird because i got three escapee shetland ewes at the moment out on the marlborough downs. Seen your post and thought ' no cant be ' . 
HAAHA!! Mine were out last night as well, my own fault as I had put them in the field with crappy fencing but more grass cos I felt sorry for them, the fencers are just finishing the fence for their new field.
Didnt feel sorry for them after me and my friend had eveentually rounded up all 20, split in 3 different groups. Especially not defiant Gretel, it's a good job for her she has lovely twin lambs for me......:-O
With good fences, they are a delight, but if they do get out, it is like herding cats :-)))
