Thanks for the extra info. I returned to the tank with a flash light trying to get more info to describe the bug to you. The bug seems to be a VERY light color, almost clear. Body is shaped like a mite the body style of almost like a tick. They seem to be running only on the sphagnum moss and only the top of the soil. I checked my frogs and they have nothing on them. Any signs I should watch out for if indeed they MAY be something dangerous to the frogs, other than them being on the frogs?