Color-changing panther chameleons are among the most disco-ready lizards, courtesy of tiny, built-in crystals that rapidly create multicolored hues. 

Embedded in the panther chameleon’s skin are not one, but two layers of crystal-containing cells, scientists at Switzerland’s University of Geneva report Tuesday in Nature Communications. Stretching or relaxing the cells helps the animals rapidly change color by changing the color of reflected light. (See more amazing chameleon pictures.)

Only adult male panther chameleons (Furcifer pardalis) have a fully developed upper layer of the cells, called iridophores, which they use to put on multihued shows for mating. When the crystals are close together, such as when the animal is relaxed, they reflect blue light. When they are combined with yellow