In some parts of fields the sheep create 'footpaths' as they walk in camel style across them.  If the sheep that is leading the line stops then all the others stop too, most wait patiently until the line starts moving again, .although occasionally an impatient sheep may go off road and overtake!   The lambs walk along the same path too.    When the sheep have been take out of the field it soon greens over again!   As you can see it isn't in a straight line!