I grew up in the midwest. Fireflies were a constant companion. I remember chasing them and trapping them in a mason jar with fabric, instead of a lid, in the ring. My firelflies were Lampyridae - a soft, easily crushed beetle whose bioluminscence came from the underside of its abdomen.
Now I live in the subtropics. We didn't see many fireflies the first year, but now that we've moved, we see them pretty regularly. I just figured they were the same insects I knew as a child. So, imagine my surprise when I picked up a click beetle (Elateridae) and found glowing patches on the extensions of its thorax (I'm not sure what these are called, but they're triangular pieces that extend down on either side of it's back). A-hah, fireflies here are not what I grew up with.
Click beetles are really cool. When they are on their backs, they are able to "click" and jump up in the air (several inches at times) and try to land on their feet. My dad introduced them to me when I was about 8 in the entry hall of the First Baptist Church where I grew up. I had hours of fun as a child by finding them and putting them on their backs to watch them jump. I'm sure this is just one step above pulling the wings off flies.
So, click beetles in the tropics? Even cooler. Apparently , they have an even brighter spot under their wings, but given how hard bodied they are, I haven't tried to pry the wings open yet. Given my curiosity, I'm sure that I will soon.