Tiny, Black Fast Moving Bugs (not ants) archived

Sitting outside. Looked over at the retaining wall out of the corner of my eye and saw 100s of tiny black bugs moving really fast. Assumed they were ants , got up to take a closer look and they are NOT ants. They are smaller than black ants (like the size of one section of a tiny black ants body). Their body has one section, they are oval in shape. Some have a white stripe across their bodies. No visible head or antenae. Move very fast like ants. Do not seem to fly. They are all over the retaining wall, brick steps. Seem to be coming in and out of the crevices of the bricks but no one source. There also seems to be tons of them in the pathes of grass (very, very dead grass) nearest to the retaining wall, deck.

Tried to take a pic but they are too small and too fast.

They are really creeping me out. The retaining wall and brick patio is adjacent to the house but they seem to be mostly in the grass, on the wall and on the stes. Not too many on the main patio and so far none near the house.