Somehow, the guys at Coral Morphologic have managed to make flatworms seem pretty cool. Well, not cool, but certainly more interesting. The video above shows off the bane of many aquarium hobbyists’ existence. These red Planaria flatworms are photosynthetic, but multiply rapidly and will cover your corals. They don’t move around too much (the speed in the video is 3x normal speed), which can cause white spots to develop on the corals they are hanging out on. They can also be quite difficult to get rid of once a decent sized population has been established.