World Fireflies Day: Our theme this year – fireflies need dark nights – highlights a growing threat to these charismatic insects. All around the world, cities’ bright lights are erasing natural darkness. Light pollution interferes with biological rhythms and blinds us to the beauty of night. It also puts fireflies at risk. Brightly lit areas obscure their magical glow, making it difficult for fireflies to detect their bioluminescent mating signals. So we hope you’ll join us in celebrating World Firefly Day 2019 by dimming your lights in recognition of the sheer delight these night-time wonders bring to us all.