Spiders (allegedly) keep this animal as a glowing prisoner to draw more prey to their webs

Fireflies usually glow to attract mates. But in this case, their light is leveraged by the jailer spiders to capture other fireflies.

The researchers noticed this behaviour while studying spiders in subtropical forests. They saw several fireflies stuck in spider webs and wondered if the spiders were using the glow on purpose. To test this idea, they ran experiments with small LED lights that resembled fireflies. Some spider webs had these glowing lights, while others were left dark.

Spiders exploit fireflies’ mating signals to boost hunting success

The results were precise. Webs with lights attracted almost three times more insects than webs without lights. Even more interesting, glowing webs trapped around ten times more fireflies than dark ones. This clearly showed that light plays a significant role in attracting prey.

According to the video footage, spiders were observed treating fireflies differently from other insects. When a moth or another bug got caught, the spider gulped it. The arachnids would leave the fireflies alone, sometimes even for an hour, which is roughly the same amount of time a firefly usually glows while trying to attract a mate. Once the glow fades, fireflies become dining table specials for the spiders.

Interestingly, most of the fireflies caught were male. Scientists think this may be because male fireflies mistook the steady glow for a potential female.

The researchers believe the spiders have learned to recognise fireflies by their light and adjust their behaviour. Unlike animals such as anglerfish, which produce their own light, these spiders are using someone else’s glow to hunt more effectively. To put it simply, these evil creatures are shot from fireflies’ shoulders.