Mike: Like the others said, they are extremely skittish, very smart, have amazing eye sight and work as a team. All these traits work to their advantage and make them one of the toughest prey to bring down.
For me, it has been the hardest game animal and most challenging to shoot. Like everyone said, if you get to shoot one, they will never give you that opportunity again unless you totally surprise them and come at them from a different location. These crows can see me deep into the house from 40yds away. I 'll be 10-12ft from the window, sizing them up and 1 will spot me and they all fly away. I think the 3 I got last year had a lot to do with luck but 1 of them was 45yds out and probably thought it was safe from my 350 .22. The others were about 30yds out and I came at them from a completely different angle, but they could not resist the dead squirrel I had put out the night before so I shot 2 of them within 1 min. which is probably unheard of. That 's 3 out of hundreds of attempts. Most of the time I didn't even get to raise my rifle and point it to their direction. They will also come every day if you leave a dead crow hanging outside. I hanged a blind on the window, tried many things, but as soon as they detect the slightest movement or see a barrel sticking out even milimeters, they 're gone.
Good luck!
Harry