In the Democratic Republic of Congo, people have been watching small shellear fish climb the steep rocks of the Luvilombo Waterfall for years. A scientist recorded this event on video in 2009, but the footage was lost. Now, 17 years later, a new study has found evidence of this amazing ability. The fish, which are about the size of a French fry, use their special fins to climb up the rocks. They have tiny hooks on their front fins that help them stick to the slippery rocks, and their back fins help them move forward. Climbing the rocks is a long and hard job for the fish, and they often have to rest and try again. Scientists are not sure why the fish climb the rocks, but they think it might be to find food or a safe place to live.