For instance, a pure yellow light such as that from a low pressure sodium vapor source does not appear as attractive to turtles as some other lights. Yellow incandescent light bulbs also are preferred if they are kept at low wattage. Examples of lighting inappropriate near sea turtle nesting beaches include fluorescent, mercury vapor, high pressure sodium vapor, metal halide, and white incandescent lighting. It is a myth that hatchlings emerge only around the time of the full moon. Hatchlings ready to emerge wait just beneath the sand surface until conditions become cool.
Hatchlings possess an inborn tendency to move in the brightest direction.
On a natural beach, this brightest direction is most often the open view of the night sky over, and reflected by, the ocean. Hatchlings also tend to move away from darkly silhouetted objects associated with the dune profile and vegetation. Hatchlings that crawl toward artificial light sources follow the same instinctive response that leads them seaward on naturally lighted beaches. It is the glaring light of artificial sources that leads hatchlings astray. At nights, artificial lights sources appear bright and glaring because they are close by, producing light that appears intense but is not bright enough to illuminate the ocean.