At dusk we saw a large number of birds that appeared to be swooping and eating the bugs around a Big Box store. Larger birds, vaguely swallow shaped, and with a similar flight pattern. Distinguishing feature a light band 1/2 way down the underside of the wing. What are these birds?

Were they Swifts ?

These massacre termites at a very high rate this time of year, because this is the time flying termites start trying to colonize other logs, meaning there are a lot of large easy targets in the air, which attract Swifts to come gobble them up, which they do with remarkable efficiency. I’ve often only just noticed a termite taking off near me, when it gets eaten by a zooming Swift.

I think you might have given me my answer, @Zaku.
I didn’t see any with banded wings, but the ones I saw pretty much had wings that matched up with the abdomen band.

I’ll read more about them!

They are Nighthawks. We get them through here on a seasonal basis. They are amazing birds to watch.

Given the description @rojo is correct as the white stripe/band on their wings is a signature of the Nighthawk . Nighthawks are usually out at dusk to dark and are mesmerizing to watch as they swoop and soar while consuming copious amounts of bugs.

Nighthawk it is!
They must consume gallons of bugs.
Interesting reading, too – no nest!