Butterflies and many other invertebrates are beautiful to watch. Without certain invertebrates, dead and decaying material would not break down and be recycled through the food web. Worms and other invertebrates churn through soil which would become compacted and incapable of supporting life without them. Invertebrates supply us with such ornaments as pearls and shells. During millions of years the sedimented bodies of dead invertebrates have become the oil deposits that we depend on today for petroleum-fueled energy.
Some invertebrates are carnivorous.
For example, jellyfishes and squids often feed on fishes, while octopuses prefer crab dinners on the sea floor. Dog whelks and some sea stars prey on shellfishes, such as barnacles and mussels. Sea snails, chitons and sea urchins are examples of herbivores that graze on algae, seaweeds and other plants. Others scavenge, and some are omnivorous, feeding on whatever food is available. Many carnivorous invertebrates rely on camouflage to lure their prey.