Genetically modified foods have been enhanced so that they are more tolerant to weather changes, more resistant to pests and fortified with nutrients not naturally found in the organisms. The two most common traits incorporated into plants are a tolerance for herbicides and an insecticide that is now inside the plant, rather than being sprayed on it. The seeds are then marketed and sold with the expectation that they are going to produce better, stronger, more nutritious food, without the need to spray as many chemicals on the crop. Per the U.S. Department of Agriculture, the most commonly planted genetically modified crops in the U.S. since 2003 are soybeans, cotton and corn. Foods that are genetically engineered or contain products that are genetically engineered do not have to be labeled for the consumer.