While moving in between areas of land glaciers erode the land around them, this eroded land leads to weathering from the sand and rocks eroded. Example The Grand Canyon
The animals believe that Snowball is the one who destroyed the windmills. This is because Napoleon blames him for all the things that go wrong.
I do not agree with them because it was destroyed by a violent November storm that blew it down. Instead of admitting that the windmill's walls were not thick enough to support it against a strong wind, Napoleon blames Snowball for blowing it up, because Snowball had drawn up the plans, the blame for its failure is partly his.