Crows have the intelligence of a 7 year old human child. They recognize faces, make tools, use currency amongst themselves, understand physics and are self aware. They've been seen doing things like dropping walnuts in intersections for cars to run over and waiting for the light to pick up the seeds from the street.
If you p**s them off, they'll tell other local murders about you and pass that hatred of you on to their offspring, making you a lifetime enemy and do s**t like drop rocks on your car windshield and punch holes in your screen door.
I know this last fact from personal experience because my grandma made enemies with the crows where she lived when they started eating her crops. She would swing her broom at them and accidentally killed one by throwing a shoe at it. Every time I visited her, they'd s**t all over my car and tuck bramble into my car's vents and exhaust. Even after she died, they peck at her gravestone and leave shells and bramble around her grave.