Lobsters are found in all oceans. They live on rocky, sandy, muddy bottoms or in burrows under rocks. They are invertebrates, with a hard protective exoskeleton. Lobsters have 10 legs; the front two adapted to claws. Lobsters are omnivores. Like snails and spiders, they have blue blood due to the presence of haemocyanin, which contains copper. Lobsters are economically important as seafood.