Forty percent of the world's insect species are at risk of extinction in the coming decades, mainly because of habitat loss, pollution, pathogens, introduced species, and climate change. Artificial light at night is included among those stressors, because it disrupts the natural behaviors of insects. More than 60 percent of invertebrates are nocturnal, so any artificial light within their habitat is going to affect them during their most active hours. "It is estimated that around one billion insects are affected every summer night in Germany, often dying from artificial light sources," the researchers explain. Insects can respond to artificial light in a few ways.