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Choosing a place to call home is one of the most consequential choices a coral can make. In the animal's larval stage, it floats freely in the ocean -- but once it settles down, it anchors itself permanently to the rocky substrate of a reef and remains stuck there for the rest of its life. Exactly how these larvae choose a specific place to live, however, is largely unclear. A new study is starting to unravel that mystery. Researchers found that the soundscape of a reef -- the combined sounds of all animals living nearby -- might play a major role in steering corals towards healthy reef systems and away from damaged ones. Healthy reefs are not exactly quiet places -- they're filled with the constant crackling of snapping shrimp, low grunts from fish, calls from dolphins or whales and other noises. It's a bit like being in a lush rainforest amid a cacophony of bird songs and animal calls. Coral larvae may take note of those sounds. On the study's "healthy" reef, which had a large variety of low-frequency sounds, larval settlement was twice as high as the less-healthy or control sites.