Think this might be Monomorium Minimum but could be wrong
Location: Northern Orlando area
Date: late June to early July
Habitat: open grassy neighborhood sidewalk
Length: 5-6mm
Color, hue, pattern and texture: black, somewhat shiny, gaster has banded brown/yellow lines
Distinguishing characteristics: too small to distinguish details
Distinguishing behavior: queens seem unusually tolerant of light and movement of their test tube setups
Nest description: usually in the dirt next to objects like pipes, walls, rocks, etc