Crows are really really smart, far smarter than chimps, dogs, and some people I know. I think Nature did a show on PBS re crows, maybe look on the website. They actually recognize individual people in a crowd. I have lots here, they had a nest in my trees. They don't bother much, but this is the really deep country, after all, not a city or suburb. Check out that program on the PBS website maybe? Might give you some hints to keep them from pestering you. Don't try to seed the lawn, and give the kitties boxing gloves? My Polly, a 15 pounder, will leap up after them. She always misses, but I'm not sure the crows don't actually enjoy the game. I have a hummingbird that baits and teases Polly as well, when she's sleeping on the chair on the porch. Wildlife interacts a lot more than we think it does, and enjoys play. I think the crows are teasing you, hee hee hee. Ever consider a scarecrow? Or contact the people who produced that program, offer them your yard as a study ground for a fee, then buy more grass seed? 60 is a lot of crows at one time! Good luck, caw caw, hugs, Marji