Greener grass

Is grass really greener on the other side of the fence. O all creatures, I think sheep are the most gullible for this ploy. Their salivary glands don't seem to work unless they are pressing against one limit or another.
"The grass always looks greener on the other side of the fence" implies that it's not, that it just seems that way, and we ought to learn to be content with what we have.

But the orchard extension to the pasture last week was really greener. And, full of dropped apples. So the new feeding pattern for Meeny, Miney and Moe is a twenty minute trip to the extension pasture where the grass is greener, the apples more lush.
But as soon as they get to the other side of the fence what are they interested in? Right, getting to the other side of the next fence.
I'm not going to go moral here, but there's something pathetic about their behavior. Is their goal to find refreshing, green, healthy grass? Or to cross another boundary. Or to get farther away from their shed?