Nematodes are everywhere. They have adapted to nearly every ecosystem on the planet and a handful of earth will contain thousands of these microscopic worms. Also known as roundworms, nematodes can range in size from microscopic to several inches long. Nematodes fill many niches in the ecosystem they range from beneficial to parasitic. Although the amount of nematode species cannot be known for sure, it is estimated from fact-based estimates of up to 40,000 species worldwide. are ubiquitous in freshwater, marine, and terrestrial environments, where they often outnumber other animals in both individual and species counts, and are found in locations as diverse as mountains, deserts, and ocean trenches. For every human on earth it is estimated that there are 60 billion nematodes. This huge group of species can be broadly split into beneficial or parasitic.
Nematodes can also be killed by Nematicides and by thermal control by processes known as soil steaming. The later is where super-heated steam is introduced into the soil causing most organic matter to deteriorate.
A nematicide is a pesticide that will kill plant parasitic nematodes.