Tidepool Tim says,  “Urchins are usually nestled up to a rock, or feasting on seaweed in packs! They can be found in cold regions of the Atlantic and Pacific Oceans. In New England, they are found as far south as Cape Cod, Massachusetts. They are quite active, moving around on their short, sharp spines and hundreds of  tube feet on their underside. If you pick up discarded exoskeleton (maybe left over from a seabird’s lunch) you have noticed a circular opening at the center of its underside. This is where the creatures mouth and five teeth are located. They crawl along the ocean floor and scrape up fine algae, also feeding on seaweeds (macroalgae).”