I am having a difficult time seeing what you are referring to.
Are they tiny white arthropods that cluster around the fecal matter?
If so, I think they are springtails. They are not a parasite- they are a decomposer. You see them around the droppings because they are consuming it. You probably got them with the soil or plants. You should not get rid of them, you should actually welcome them, they help keep your tank clean. In fact, many people purchase and culture springtails for terrarium use.