On the quiet island of Little Cayman, an even quieter area called Mahogany Bay holds the biggest population of iguanas around. There they normally love to sunbathe and laze about in peace, but recently the local humans have been noticing a big change. The iguanas seem restless, becoming more aggressive and making spooky sounds at all hours of the night. And if the humans could speak their language, they would hear a distinct rallying cry: "Drive the...