Despite popular myths, there is no scientific evidence that beetles produce a glowing toxin for defense. While some beetles, like fireflies, exhibit bioluminescence, this light is generated by specialized organs using chemical reactions—not by secreting a toxic substance. 

The light primarily serves for communication and mating rather than predator repulsion. In reality, most beetles rely on other survival strategies such as camouflage, rapid movement, or physical defenses to avoid predators. 

The myth likely stems from a misunderstanding of the bioluminescent abilities seen in certain insect species, which are often mistakenly attributed to all beetles. 

Accurate scientific research shows that beetle bioluminescence, when present, is a natural adaptation for specific functions and does not involve the production of any toxic or glowing defensive fluid.