You are what you eat—or, at least, you may turn the same color as the things you eat. Flamingos are pink because they eat shrimp, and even humans can turn orange if we consume too many carrots or tomatoes. The agents responsible are pigments known as carotenoids, but scientists have now found that at least one animal doesn't need to eat them to change color. Instead, tiny insects called aphids picked up the genes needed to produce carotenoids from a fungus sometime during their evolutionary history. That makes aphids the first animal known to produce its own carotenoids, researchers report tomorrow in Science. The scientists remark that it is curious that other animals haven't acquired a means to produce carotenoids, given the many important functions they perform, such as strengthening the immune system.