Or, Lightning Bugs as us Chicagoans call them.

One of our projects is a “bugs in a jar” effect. Basically, we fill a mason jar with twigs and such, then put in electronically controlled yellow LEDs. They simulate the random look of fireflys in a jar. It’s been done before, but it’s a cute effect, and would make a nice (subtle) nightlight for a childs room.

Here’s a shot of the Incubator, as it were.

After some experimentation I came up with a way to ‘mass produce them’ (at least in the quantities I need. I took a piece of clay, flattened it out, covered it with Saran Wrap, and then made gooves with a round chopstick. Next, I took my handy caulk gun and loaded it with GE black Silicone. It’s labeled “Blacktop and Roof” repair. It’s great, because it dries pretty quick, and remains flexible.

Then I make a 1 1/2″ line of caulk in each groove. Then, I bend the leads of an LED and stick one in each end of the sticky blackness. I push the LEDs into the already laid caulk because it’s much easier than trying to get the caulk “just right”.

Once it’s dry, I’ll snip them in half and have two fireflies for each groove of caulk. You don’t need to be overly neat, since you can easily trim the Silicone with scissors. Also, if you try an do this, slide the LED so that the bottom (in photo) half is covered in some caulk. That gives a more realistic look, as the LED gets hidden and only shows at the bottom & back of the finished “bug”. I bend the leads to give the little guys legs.

You can see a dried, and slightly trimmed, version standing up in the above photo. We’ll paint a little yellow along the “wings” to make it more real looking, though they will be stuck in a jar, so they don’t need to look perfect.

Once these are dry and cleaned up, I’ll try posting a video of them in action.