This is the time of year when Nicole Hughes gets constantly distracted by the fall foliage as she drives around North Carolina. "I'm always looking," says Hughes, a biologist at High Point University.

Fall is just around the corner, when leaves begin to change their colors. But have you ever wondered what causes them to transform? "Plants make their food using sunlight and something called ...

Scientists know why leaves turn yellow in the fall: Chlorophyll breaks down, revealing the yellow pigment that was there all along. But red? Red is a different story altogether. Leaves have to make a ...