Even though whale sharks have huge mouths that are 5 ft long doesn’t mean they have to eat big food like fish here’s why. Whale sharks digest plankton a small animal they all kinds of small animals small as (8/100 of an inch ). Small such as fish eggs, squid,and sometimes big fish tuna. plankton are a micronekton a small fish. Whale sharks do have teeth,but their tiny. So they use a thing called filter feeding,they open their mouth and throws its head side to side to eat. A cool thing about a whale shark is….. It can turn its stomach inside out when it eats trash. A whale shark may filter the same amount of water in an olympic sized swimming pool. A whale can use its nostrils to find food. A whale shark will not eat you unless you’re smaller than 0.08 inches.