So I was at the base of the Rock Falls waterfall here, looking for salamanders in the stream in the dark of the night (as you do) when I turned off my flashlight for a moment and I noticed several faint glowing points along a wet wall of the bank (on the left side when facing the waterfall, and to the left of the wall covered with liverworts) at about eye level. At first I thought it might be a bioluminescent fungi or something but upon closer inspection they were these little things sticking out of holes. The holes were probably no bigger than 0.5 cm. When I blew on them they retracted into their holes (3rd and 4th photos). I took some "nighttime" exposure shots with my phone which show their blue glow (not very good photos of course as I didn't have anything to stabilize the phone, so they are really meant just to show they were glowing). Some of this glow is visible in the hole in the 3rd and 4th photos. I didn't capture a specimen but I have to imagine they will still be there in the future.

Maybe Orfelia fultoni? Not sure if this species is right as I read that it occurs in the Appalachians. I haven't been able to find any info about bioluminescent insects which occur in Louisiana aside from fireflies.