In the lecture, professor gives two advantages of subsurface locomotion. And he gives two examples of sandfish. First, sand fish uses subsurface locomotion to avoid heat. They are cold blooded animals so they dig in to underground and control their temperature. By dig into underground, they can avoid heat. Second, sandfish can detect the vibration withought their sight. On the sand, there is some obstacles so it is hard to find the prey. However, underground amplify the prey's vibration so sandfish can find prey much easier than on the sand. Therefore, these are the two advantages of subsurface locomotion.