Insect and Spider Identification: What is this insect?, 1 by Emptybee

Emptybee wrote:
We live in North Texas, and had some horrendous storms this week. The day after, our downstairs bathroom was invaded by these small bugs (literally hundreds of them). They are dark, with small antennae, not winged, and seemed to be everywhere in the bathroom -- on the walls, ceiling, floor. They are about .5 CM long. It was not apparent where they entered the room or how. PLEASE -- can anyone tell me what this is, how we got it, and how we never get it again? Many thanks