Hi Hort
Super sol 45 animation.
Seems to me that the soil is bound together by forces yet invisible to the microscope and those moving small objects are merely sitting on the soil and crevices and are disturbed by the probes which stretch the soil matrix as they are pressed in. i.e. the probes' force is not limited to merely just a very short distance around the probes but much further afield.
Another possibility is that there is life there somehow reacting to the very unusual insertion of the probes in their vicinity.
Winston