{"fact":"Once crows learn to peck a key for food, they don't keep doing it if the food comes regardless.  In one study, crows stopped pecking the key when they realized it didn't control the food delivery.","context":"When three of these crows were again exposed to keylight-food pairings (automaintenance), their responding attenuated over time to near the zero level.","source":"Robert W. Powell; William Kelly; David Santisteban, Response-independent reinforcement in the crow: Failure to obtain autoshaping or positive automaintenance, 10.3758/bf03337554","index":36}