Mystery in the Dark

Lights on termite mound, Pantanal, Brazil

Never believe the conventional wisdom. When we spotted these striking lights on a termite mound on our last night in the Pantanal, we were told they were caused the termites themselves, on just one or two nights a year. (I'd never heard of bioluminescent termites before, but what do I know...?)  But why?  Not for mating, like fireflies, surely. There was no Google handy out there, so I had to wait until I got home to investigate further.  And wouldn't you know it - the story was much more interesting.
The green lights we saw were the glowing abdomens of Pyrophorus, or click beetle, larvae which burrow into the edges of termite mounds and use the lights to attract other insects - as prey.  Apparently some of these glowing beetles are found in the US, in Texas and Florida.
This was a 30-second exposure at ISO 2000, so there is little depth of field, and a fair amount of noise. But it was good enough to at least capture this rarely-seen behavior - and learn a new story.

Nikon D3, with 24-70mm lens