From a population standpoint, insects rule our planet. Scientists have gotten around to naming almost 900,000 different species of insects, but some experts suggest that there may be as many as 30 million more species that haven't yet been christened [source: Smithsonian]. These same scientists estimate that about 10 quintillion--that's 10 with 18 zeroes behind it--insects are alive on Earth at this very minute.
With numbers this staggering, it's no wonder that insects affect our lives and civilization, influencing everything from religion to agriculture to technology. Sometimes the insects' actions are what we perceive as helpful, such as the dung beetle, the sewer worker of the insect world. Sometimes the insects seem to cause harm, like the deer tick, whose bite can inflict Lyme disease. Other times, the purpose of the insect is more ambiguous. It's all part of the world's biodiversity, where the actions of one species often complement another. Each species depends on the other to ensure survival, sometimes in ways we don't yet know.
With that cooperative spirit in mind, keep reading to discover 10 important insects and just what they do to earn that ranking. You'll find out why roaches may not deserve their bad guy label and why the ancient Egyptians put a bug on the chests of their dead.