Serious population explosion of soft bodied little mites after very rainy period. At first, thought it was frass and crushed some and noted a very distinct citrus smell. Magnified, I could see they were mites (soil/mold mites?). They measure about 0.8 mm length and around 0.5 mm in width (1.0 mm graduation marks shown in second photo). Don't think (hope) they are mammalian biters.