How Can Cockroach See at Night?
WouterCockroaches have the ability to see in low light conditions, and researchers from the University of Oulu, Finland, recently discovered that the creatures can detect moving objects. They do this by accumulating information from thousands of photoreceptors. This information is then summed to make the creatures see.
The eyes of a cockroach are located on the head and are black and bean-shaped. They are made up of more than 2000 units called ommatidium, each unit acting as a visual receptor. This allows cockroaches to detect movement within the optical field, but they cannot distinguish between humans and other vertebrates. Despite this, cockroaches can detect movement with their antennae and tiny hairs on their legs, and they can sense even the slightest touch.
The roach has excellent vision, but its eyes are not as sharp as ours. Their lenses are misshapen towards the outside of their eyes, and some of them even have abnormalities in the middle. This makes it difficult for them to see in red light, but they can see well in green light.
Cockroaches are nocturnal creatures, meaning they spend most of their time hiding from sunlight and feeding on left-over food. Their nocturnal habits also dictate their activity rhythms. They are inactive during the day, and start hunting for food at night around four hours after the lights go out. During this time, they feed on garbage, crumbs, and other food debris on the floor. They also feed on fresh and rotting food matter.
