Flexi Says: Although roundworms have simple nervous systems without developed sense organs, they are still able to sense and respond to environmental stimuli including chemicals in air (smell), food (taste), pressure (touch), and light (sight). Scientists even recently discovered that the worms avoid blue light, which means that they can sense color even without eyes! Scientists determined that their ability to sense color comes from two genes that are present throughout the animal kingdom, including in humans. The scientists are still researching which cells in the roundworms express these genes to detect color. The roundworms use this sense to avoid blue toxins that are secreted by bacteria in their environments.
