Crows are smart. They are social. They have a hierarchy, a recognizable language and can be trained. I have some chimes at the back of my farm house. Rather than throw scrap food away, I take it out the back, ring the chimes and within a minute the crows arrive.
At one time, when I was a boy, crows blackened the skies over corn fields in Pennsylvania. No longer.
The big murder of crows have vanished, but their antics continue to amuse their admirers.