Krill are small, shrimp-like crustaceans found in oceans around the world, particularly in the Antarctic region. They play a crucial role in the marine food web, serving as a primary food source for many animals, including whales, seals, and penguins. These tiny creatures are usually about 1 to 6 centimeters long and are known for their swarming behavior, often forming large groups called swarms. Rich in nutrients, krill are also harvested for their oil, which is used in dietary supplements and animal feed. Their high levels of omega-3 fatty acids make them popular for promoting heart health. Protecting krill populations is essential for maintaining the balance of marine ecosystems.