When the water returns, they open up their shells to kick food into their mouth with their feathery feet. Brown periwinkles graze on algae, while white dog whelks use acid and a sharp tongue to drill through the shells of other snails. Brown rockweeds drape the middle zone of the tidepool. Air bladders let them float on the surface of the water at high tide where they can get the best light. Beneath the seaweed starfishes and sea urchins cling to the rocks with sticky tube feet.
Mussels hold on with lifelines they weave themselves.
Just below them grows a red seaweed, Irish moss. It was once collected along the coast of Maine with long-handled rakes. It was used to thicken puddings, ice cream, milk shakes, and toothpaste. Green crabs wander throughout the tidepool, always looking for a chance to grab a meal. They keep close to cover, though, to avoid being noticed by a sharp-eyed herring gull.