Minecraft wiki entry for Turtle, associated text: Turtles can both move around on land and swim in water. They move slowly on land, but they can swim at a fast speed in the water. Like other passive mobs, they move around aimlessly and flee when attacked. When on land, they generally attempt to move to the nearest water source with direct sky access. When in an enclosed area, such as a player-made enclosure, they generally swim in circles if the water is in the area, and rarely go on land to explore, if there is any.