A number of years ago A family that I know asked me to take care of their farm for a week while they were away at the beach. One of my responsibilities was to walk the fences in the sheep pasture and extract sheep that had stuck their heads through the fence. The sheep would shove their heads through the fence to eat the grass growing on the other side. When they were done eating they would back up until their ears touched the fence and then they wouldn't go any farther. All I had to do to get them out was lay their ears forward and then they would just back up until they were clear of the fence. I'd have to agree that sheep aren't all that intelligent.
