In the morning, the blind Cyclops lets the sheep out to graze, feeling their backs to ensure that the men are not escaping. However, Odysseus and his men have tied themselves to the undersides of the animals and so get away. As he sails off with his men, Odysseus boastfully reveals his real name, an act of hubris that was to cause problems for him later. Polyphemus prays to his father, Poseidon, for revenge and casts huge rocks towards the ship, which Odysseus barely escapes.