# Fireflies

**URL:** <https://boards.straightdope.com/t/fireflies/68987>\
**Category:** Factual Questions\
**Created:** [June 15, 2001, 11:37pm UTC](https://boards.straightdope.com/t/fireflies/68987 "2001-06-15T23:37:25Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![CuriousJohn](https://avatars.discourse-cdn.com/v4/letter/c/58956e/32.png) [@CuriousJohn](https://boards.straightdope.com/u/CuriousJohn)\
**Post date:** [June 15, 2001, 11:37pm UTC](https://boards.straightdope.com/t/fireflies/68987/1 "2001-06-15T23:37:25Z")

</div>

I was just wondering, what’s the deal with fireflies (lightning bugs, whatever you want to call them) and how do their “light organs” work?

```
                             John
```

---

<div class="post-metadata">

**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\
**Post date:** [June 15, 2001, 11:47pm UTC](https://boards.straightdope.com/t/fireflies/68987/2 "2001-06-15T23:47:38Z")

</div>

[this](http://www.straightdope.com/mailbag/mfirefly.html) doesn’t answer your question but Cecil said it.

---

<div class="post-metadata">

**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\
**Post date:** [June 16, 2001, 1:45am UTC](https://boards.straightdope.com/t/fireflies/68987/3 "2001-06-16T01:45:33Z")

</div>

Fireflies exude the chemicals Luciferin and the enzyme Luciferase that combine with Adenosine DiPhosphate (ADP) to produce a momentary glow. I learned this, as a kid, from a **Hawkman** comic book. Who says they aren’t educational?

Years later I learned that Luciferin+ Luciferase mixture can be used to make ADP light up. Hook your microscope up to a photocell and ou have a way to measure ADP concentrations. Neat idea.