1) Lightning bugs (aka fireflies) prefer warm, humid climates and are native to areas east of the natural barrier of the Rockies. They're rarely seen in the more arid states west of Kansas - and those few species that can be found in the Rockies are not the flashing variety.
2) We haven't seen any in the 25 years we've lived in Wyoming (to our sorrow)
3) When we've lived in places with lightning bugs, we never saw them cluster around lights. In fact, along with development, researchers cite light pollution as a probable major factor in the worldwide decline in lightning bug populations, since it interrupts the flash patterns lightning bugs use to communicate and attract mates.
4) Every time our neighbor has tried to convince us, he's had a beer in his hand. ;-)
What we have seen are small moths flying around the streetlights, whose light reflects off their wings and makes them appear to be glowing. So we think those are probably what our neighbor is seeing and mistaking for lightning bugs.
So maybe our neighbor meant to say lightning and not lightning bugs. :-)