Even glaciers flow, otherwise they would over time become as thick as cloud layer that provides that rain drop or snow flake. Its just that speed of flow is...

Even glaciers flow, otherwise they would over time become as thick as cloud layer that provides that rain drop or snow flake. Its just that speed of flow is... glacial. 1 year on glacier, once snow is compressed into ice which takes few years, is represented by maybe 1-2m layer in European Alps. Thats why glaciers have crevasses - they bend as valleys flow (or over some hard bottom bumps that weren't grinded flat yet), and it cracks at those bends. Just like say chocolate on surface of cold Snickers bar if you try same bending