Montgomery (1955) allowed rats to explore elevated and enclosed Y -mazes and found that rats in elevated mazes made fewer arm entries than rats in enclosed mazes. The type of maze had no effect on the order­ liness of the exploration. Lester (1967b) suggested that this latter result is misleading. Given that rats in elevated mazes have higher fear levels than rats in enclosed mazes, then rats in elevated mazes should show more repetition than rats in enclosed mazes. Con­ sider a rat in Arm A who enters Arm B and then turns around to face the choice point again. The higher the rat's fear level the more likely it should be to enter the most recently visited arm, Arm A, since that arm should arouse less fear than the arm not recently visited, Arm C. Lester suggested that Montgomery's failure to find this result might have arisen from his consideration of the total exploration period rather than the first choice. After the initial choices, all arms have been visited and so may not differ in the fear that they give rise to. Mowrer (1960) has suggested that a hungry rat is a scared rat. Mowrer talks of rats developing thirst fear and hunger fear (1960, pp. 147-148). Thus, it might be expected that deprivation versus satiation should have a similar effect on exploratory behavior as does elevating or enclosing the maze. The present experiment sought to test these ideas. Method The Ss were 80 naive male albino rats of the Charles River Breeding Laboratories strain CD with minimal experience of handling. They were 120-124 days old. The apparatus consisted of two Y -mazes made of wood. Both had arms 22 in. long and 6 in. wide. One was enclosed, with arms 6 in. high covered with hard­ ware cloth. The other was elevated 25 in. An observer was seated behind a screen equipped with an observation hole. The rats were run either in elevated mazes (El) or enclosed mazes (En) and either with 0 h or 24 h of food deprivation. There were four groups each with 20 rats: El-O, El-24, En-O, and En-24. Each rat was placed in the Y -maze for one 20 min exploration period and the sequence of arms entered was noted. An entry into an arm was defined as made when all