Sometimes, a strange kind of crop sprouts in the sandy bottom of the Red Sea — eels. These garden eels grow up to 3 feet long, and about a half-inch in diameter. They live in holes in the sea floor, into which they can retreat at any hint of a predator. Even when they’re feeding on tiny animals called zooplankton, they stay anchored in the sand. They secrete a kind of mucus that helps them stay put. But why stay anchored if you can swim? And they can if they want to. Wouldn’t that get you more food? Apparently not. In low current, they stretch out and snatch any prey within reach in any direction. In a faster current, when free-swimming fish have trouble chasing prey, the eels adopt a question mark shape. That lets them hold steady and still feed on plankton as they sweep by. An analysis by researchers found the drag on their bodies was up to four times less than it would have been if they were straight up — that is, when the researchers could find the eels. This shapeshifting talent has allowed these eels to colonize the sandy sea floor, where other fish have trouble getting a grip. Sometimes, the stay-at-homes get all the good plankton.