Movies of 2X sped up C. elegans as they chemotax toward a point source of 10-2 benzaldehyde. The corresponding clip of worms after exposure to benzaldehyde (10-4) for 80 minutes in the absence of food.
Nematodes (or roundworms), are generally slender worms, circular in cross section. They are remarkably uniform in structure but vary a lot in size and way of life. Some live as parasites in other animals, some are parasites of plants, and some live free in soil, marine mud and decaying organic matter.