Heart cockles have windows in their shells made from natural optical fibers, allowing light through to the algae inside them.

Cut out one large light green heart and four medium-sized black or dark green hearts (for the panda’s ears and eye patches). Cut a little heart for the nose. Glue the smaller hearts on top of the ...

Hidden in a bamboo stalk in China sat an elusive creature with a “heart-shaped ... made it difficult to find — but not impossible. When scientists finally found the small animal, they ...