Population-wise, we might as well dispense with the idea that we run the planet. A population of 7 billion might sound large to us endoskeletal bipeds, but it's peanuts next to roughly 10 quintillion (10,000,000,000,000,000,000) living insects. The population of the United States measures around 320 million. Some soil studies have found that many insects in a singleacre [source: Smithsonian].
For insects with high mortality rates, fecundity means survival. But bountiful babies offer evolutionary perks as well. Large populations help insects make the most of new niches and prospects. They also help insects develop resistances to whatever bug juice we throw at them. Fitness traits develop through random favorable mutations, and large populations mean large numbers of tickets in the genetic lottery [source: Yeates].
In addition, population pressures push insects to spread out. More geographic isolation and less gene flow from one end of the populace to the other helps to bring about new species. For existing species, large populations help ensure stability by lessening the impact of genetic drift [source: UC Berkeley]. They also face fierce rivalry within their ranks, a problem some insects deal with using a little social engineering [source: Capinera].