How to Make Fireflies in a Jar

Fill a jar with fireflies on a warm, summer evening.

Light up the night! The firefly, Photuris pyralis, is not really a fly; it's a winged beetle. There are more than 136 species of fireflies, or lightning bugs, and all of them use the two chemicals luciferin and luciferase to create their light. Luciferin creates the light; luciferase is an enzymatic trigger; and oxygen provides the light's fuel in a process that involves the conversion of adenosine triphosphate (ATP) to energy. Collecting a jar filled with fireflies is easy if you know where, when and how to do it.

Things You'll Need

• Glass jar with a non-perforated lid
• Apple slice
• Fresh grass

Instructions

1. Look for fireflies in the right places. Fireflies often gather along country roads. Fireflies prefer fields of high grass, but you will find them in many different habitats: forests, swamps and along lake shores and creeks, for example.

2. Look for fireflies at the right time of the year. Different species of fireflies are active at different times of the year, but you will be most successful looking for fireflies during warm months of the year from May through September.

3. Look for fireflies at the right time of the day. Fireflies are most active just after sunset and for an hour or two after. Some species of fireflies are active all night, however.

4. Catch a firefly gently in your hand when you see the firefly's light in the air. Fireflies are harmless. They do not bite or sting, they are not poisonous and do not carry disease.

5. Remove the lid from a glass jar and open your hand over the mouth of the jar to release the firefly you caught into the jar. Brush the firefly from your hand into the jar if it doesn't leave your hand. Replace the lid on the jar.

6. Continue catching fireflies until you have as many in the jar as you wish.

7. Remove the lid from the jar and blow over the mouth of the jar once a day to renew the oxygen in the jar if you keep your fireflies in the jar for more than a day. Do not punch holes in the jar lid; this can dry out the fireflies.

8. Place a slice of apple in the jar to provide humidity. Place fresh grass in the jar to provide your fireflies with hiding places.

9. Keep your fireflies within sight of a window so they know when it's day or night. Be careful not to put them in the Sun because the closed jar will get hot and kill them.

10. Release your fireflies when you are finished enjoying and studying them.

References

• Texas A&M University; Fireflies/Lightning Bugs; Linda Brown; 2006
• Ohio State University; Ohio State University Extension Fact Sheet; Firefly; William F. Lyon
• University of Florida; Fireflyer Companion; J. E. Lloyd, ed.; 1994