Below is an amazing video of time-lapse photography showing flying insects near streetlights. I have never seen anything like it.
The video shows (in an unique way) what you already know. Flying insects are attracted to lights. You might not know that many of them are killed each night by the lights they are attracted to. To most people that sounds like a good thing, right?
Check out these statistics from the Starry Night Lights Blog:
Studies show that the average street lamp kills at least 150 insects each night it is lit. Multiply that by 365 and you get 54,750 insects killed by one lamp in a year. A city block has at least 4 usually more in the range of 8 street lamps. That means that one city block is knocking out 219,000 to 438,000 insects per year.
While flying insects are an annoyance to humans, they are food to birds, bats, reptiles & more. Read the full post, quoted above to see the full impact that streetlights can have on the animal kingdom.