A murder of crows

I have watched the crows fly to go roost every dusk for years and years asking "where do they go?" And someone explained that.  

Thousands of crows have gathered nightly at the University of Washington's Bothell campus for at least 14 years. The “murder,” or group, of crows in Bothell can reach a peak of up to 16,000 birds. Even those who witness the phenomenon regularly are still awed.