Geese that are exposed to a moving box during the first two days after hatching will imprint on the box. geese that are totally isolated from any moving objects during the same period will never imprint on anything. these results show that geese have an instinctive tendency to avoid moving, box-shaped objects. the first two days after hatching are a critical period for imprinting in geese. young geese must see some type of box to imprint correctly. geese must be exposed to their mother more than two days after hatching to imprint on her.