One Amish neighbor has a Martin colony and even sells supplies. He is quite an expert on it and even has a telescope to watch them. Several years ago there was a cold snap after the birds had eggs that were hatching. There were no flying insects available and the babies started dying. So he ordered several pounds of flying tree crickets, hoping they would fly when released and feed his birds. But it was still too cold and the crickets would not fly. So the word was sent out and we all were over and hand tossed crickets, one at a time, into the air. The Martins quickly learned what we were doing. It was the strangest feeling to see this low flying bird line himself up with you. It's just like an A-10 fighter jet locking on a target. Then at the precise moment I was to underhand toss the cricket straight up. He always caught them and flew back to the nest. Next cricket please. I wore out my arm.
