Gerald Wilkinson, a professor of biology at the University of Maryland, decided to find out what was going on among the vampire bats. He spent many hours looking closely inside the trees where vampire bats were gathering. He also set up acolony at the University of Maryland so that he could keep a closer watch on particular individuals and which bats they fed and were fed by. Wilkinson noticed that sometimes one bat would do the feeding and at other times it would be fed by the others, and it was this difference that gave him a clue as to what was going on. プロビジョンレッスン９パート３前半よろしくお願いします
