OK, OK, Frances, you clean the backs of the cupboards...
What about thrips? (Thrips is singular -- plural is thripses I suppose.) Also known as thunderbugs.
These do fit your description, being blackish, thin and about that length. They have wings, which may not be obvious, as they fold them along the body. They fly about in hot, humid weather, and tickle when they run about on your hot, sticky skin -- they don't actually bite, but the tickling seems worse. Some other thripses are crop pests, including ones which look like tiny white moths.
Could they be aphids? Greenfly or blackfly -- roundish bodies, clumsy, spindly legs, wings sticking out above, from 1 to 3 mm. Very common in cornfields and gardens, where they suck plant juices. They don't bite humans though.
And what about midges? Now they do bite! Very small (0.5 mm?), proportioned more like a tiny housefly. They tickle and bite, leaving a little mark like a lovebite, which itches. They like tender skin, such as forearms, necks and faces, especially around the eyes. If you squash them, more soon appear. They come out on warm, damp evenings, except in Scotland, where they hover like smoke over the ground and eat you alive all summer long. Not usually indoors though as it's too dry. Citrus oils seem to repel them -- rub your skin with orange peel.