Giant clams have big blue and green living iridescent cells on their lips. Researchers always wondered why it was necessary for the clams to have living iridescent cells on their only opening. It turns out the cells magnify light so that algae can grow better inside the clams. Light that passes through the clam’s lips is magnified five times before it reaches the algae—an increase that could be used to make solar cells more efficient. Solar cells stop working when they get to hot, and the way the clams employ iridescent cells could be applied to a cooling mechanism so solar cells stay cool.