LIGHT INTERFERENCE

Community development has also contributed another possible problem for fireflies: too much light. Fireflies use their lights to communicate and find possible mates. They even have a language of sorts based on the flashing patterns they produce. These patterns can be a callout to specific fireflies -- such as when they are looking for mates -- or they can be messages to the whole community of fireflies, such as when they want to warn others.

However, the artificial lights caused by human communities, towns, and cities probably interfere with their light communication network. It has been observed, for example, that their synchronized light patterns are disrupted by a passing car with its headlights switched on.

All these lead to two effects: fewer mating pairs finding each other and more fireflies withdrawing from lightdisruptive areas, going further and further away from human communities.