Ours have amused themselves of late by escaping from their pen.
Now by that, I don't mean 'oh look, a hole, let's squeeze through it' type escaping. No, we're talking proper soil down trouser legs escape from Colditz type escaping. The thing is, they have been inside for what, 6 weeks now, and have never got out. However, they actually dug a duck sized hole under a sheep hurdle the other day and then went walkabout.
Perhaps they're not as thick as I previously supposed!