When I was a teenager I set a live trap in my yard to catch squirrels and a Blue Jay got caught instead. When I went to let him out, he started to squawk draw other Jays. The other birds dived on me and peck me in the head drawing blood. Let me tell, they peck hard. Another time I tossed some raw peanuts in the yard. A Blue Jay landed on the ground and would pick up a peanuts and shake it, drop it, pick up another shake, until he found the best one. He flew up in a tree, ate it, then flew back down to start the process all over.