Glow-in-the-Dark Spiders: What’s Real and What’s Photoshop?

Many viral images show brightly glowing spiders — but are they real? Some spiders do fluoresce under UV light, but none are truly bioluminescent like fireflies.

Fluorescence vs. Bioluminescence

Fluorescence means the spider reflects UV light back as visible colour. Bioluminescence means it creates its own light. No spider has been shown to do the latter naturally.

Which Spiders Glow?

Jumping spiders, some orb weavers, and others in tropical regions have shown fluorescent properties under black light — but it’s rarely visible to the naked eye.