There was a time when a light in the dark of the night was a beacon. Light has always been a source of hope; like a lighthouse warning ships of a hidden reef or the warm glow of a fire on a cold winter's night. Since humankind learned to control fire, a light in the night has been a comfort to us all and provided a sense of security.
In ancient times, a fire may have been used to ward off large meat-eating animals and protect our ancient ancestors. In modern times, a child may use a nightlight to keep out the shadows and the boogeymen that lurked in them. To humans, light has always been a security blanket and a comfort, protecting us from the unseen waiting in the darkness.
Over time it seems that our use of light has gone from helpful to hurtful. There is growing evidence showing that a brightening night sky can be harmful to human health. It also appears that artificial nighttime light affects insects and other animals. Here are three reasons why we may need to turn off the porch light at night.