Tiny little bugs!!
Your photo won't enlarge very well, so I can't be positive of the identity of your tiny bugs, but I am pretty sure these are a type of mite. If I had to make a guess, I would say that they are mostly like a type of long-legged velvet mite (Family: Erythraeidae) or possibly clover mites (family Tetranychidae). There is no way for me to tell for sure without the actual specimens or an extreme close-up photo, and these could be easily be something else with which I am not as familiar. However, both these types of mites are known to build up large populations in fields and yards, and when they disperse, they often end up invading homes. For the most part they do not bite humans and are only considered a nuisance, but when squashed, can leave reddish stains on furniture, floors, walls, etc. Long legged velvet mites live in the soil, with immature stages being parasitic on other small invertebrates and adults being predators, while the clover mites feed on plants. Apparently heavily fertilized lawns can lead to large populations building up, whence they begin to migrate. Alternatively, if these are in nearby fields or crops that have recently been harvested or dried up, then they could be migrating from there into your yard. Again I can't be absolutely sure what type of mite these are without seeing actual specimens, and even then, it would be better if they were sent to a mite identification specialist, which I am not, for determination. Regardless of what they are, the problem is getting rid of them or keeping them out of your home. Various home and garden insecticides, especially those containing pyrethroids, should control these tiny mites, if they become a real nuisance. It is recommended to spray a band about 6-10 feet wide around the perimeter of your house to keep them away. You could also treat around doors, windows and vent areas where they might enter. You can also treat your deck or patio area with these same insecticides. Without knowing specifically where they might be coming from, if they persist, then you may need ot have your entire yard treated. If you begin to see them inside the house, I would recommend frequent vacuuming to remove them, rather than indoor insecticides, although those will also control them. Even though these may not be clover mites, I have attached a link to a fact sheet that gives more information about controlling them which should work on whatever type of mite they actually are.