Lighting is a powerful stimulus on behavior. If there s enough of it, it can make them act in ways they wouldn t normally. If enough light is present say, in a well-lit neighborhood it s possible that animals living there would be stimulated to act as they do during longer days. Adult female sea turtles will not emerge from the water to nest and lay eggs on beaches that are bathed in artificial light. Many behaviors influenced by changing light from night to day and the seasonal increases of longer days involve hormones.
Hormones regulate growth and immune functions.
But they re not produced all the time. If they don t shut down, you overload the body. It can t get rid of them. Hormones are toxic in the wrong amounts. Indeed, a 1998 study at the Mary Imogene Bassett Research Institute in Cooperstown, New York, found that cancerous liver cells in lab rats grew rapidly when they were constantly exposed to light.