Common Dolphin (Delphinus capensis) upside down feeding. There may be many reasons why Common Dolphins chase anchovies and other small bait fish upside down. Some believe their eyes are better adapted to focus on a single target below the jaw, so when the prey is on the surface, they roll over. Others believe the white underbelly of the counter-colored dolphins helps to disorient the prey making them an easiere target. Physically, chasing small fish up against the surface helps to "pen them in," and limits their escape opportunities in the three-dimensional world of the ocean. Swimming upside down may also be just a lot of fun...why not enjoy the hunt?