Secondary customers take in herbivores. They are at the third trophic level. Within a desert ecosystem, a secondary customer could be a snake that eats a mouse. While in the kelp forest, sea otters are secondary shoppers that hunt sea urchins. Greggs, a bakery and food outlet from the U.K., https://www.generationgenius.com/videolessons/food-webs-video-for-kids/