Lightening bugs.
Fire flies.

Crawdads, Crawdaddies, Crawfish, Crayfish, Mudbugs - all the same.

As kids in east Texas, we called them Lightening Bugs. A few folks called them Fireflies, but everybody knew what was being discussed.

In the summertime, we would catch them and put them in a jar.
The "winner" had the most, but we always turned them loose before going inside.