Mysterious black lice?

I have a Bermuda Fish Tank, as I like to call it. Things come across to appear and disappear as they please, including the mysterious appearance of snails, white spot, fungi, weird little white slug things, and the literal vanishing of several of my toddler fish.

No illness I have ever gotten has be traceable, mainly because I seem to get them six months after I closing introduced any fish.

My latest problem is tiny (probably 1mm long) little black parasites on the caudal fin and hide of my 5-month outmoded balloon molly. I noticed them a couple of days ago. My molly was pure white as a fry and now she is stupid brown with a white belly and the black spots. I just thought they be black spots at first but tonight I was watching her and it seriously looked like one of the black spots had little legs! And they give the impression of being to be sprouting up overnight. Yesterday she had like 3 spots, now she have about 6. I was watching her for a while and after investigating her with a magnify glass it seems as though they are raised (if it be just patterning it wouldn't be raised) and they have little antennas and legs.

I did some research and thought conceivably it could be black ich, but she eats fine, and although she doesn't flick against things, she rubbed against the back wall a few times.

What's wrong with her? Her mother is surrounded by isolation from the eternal whitespot that keeps appearing when she is in the main container but vanishes as soon as I put her in the isolation tank (see - Bermuda Fish Tank!) and I put surrounded by a full dosage of fungi treatment (which has whitespot treatment in it) in her reservoir and a half-dosage in the main tank (because of the tetras and loaches) every 3 days to try and rid it of any traces of bugs. I know most fish treatments snuff out invertebrates and assumed it would have killed the parasites?

What have my molly got, how do I treat it and why hasn't the fungi treatment helped?

Thankyou to anyone who can help.
Answers:    You be right to assume it is black ich and needs to be treated like regular ich. Not all fish flash or rub against things near ich. That is just one sympton.

You will have to treatthe entire tank Remember to remove any carbon filter you may be running
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