The pumpkin toadlet (Brachycephalus ephippium) of Brazil is flaming orange, smaller than a nickel, and deaf to the mating calls of its own species. How the diminutive amphibians found mates amid the leafy chaos of the rainforest floor was a mystery. Now, scientists searching for answers to this acoustic riddle have discovered something unexpected: This toadlet glows, Mongabay reports. The pumpkin toadlet’s back and head glowed blue under ultraviolet (UV) light, researchers reported last week in Scientific Reports. This UV light show could help these toadlets find love in the dark, but researchers still need to figure out whether the frogs can see it. The glow also comes from a surprising source: a fluorescent skeleton shining through translucent patches of the frog’s skin. If the pumpkin toadlet can’t see UV light, researchers speculate that the glowing bones may serve to warn would-be predators of the toadlet’s toxicity.