how long do they stay hid from the naked eye?...what should i treat with...i found a louce on one of my females today...i have had this female for over a month no lice...i moved it to my 180gal (witch has been going for over a year with no lice...yesterday nothing, this morning i didn't see anything, then a few min ago i was looking at her and i saw it between here eyes...i scooped her out in a cake pan and with a tweezers plucked that hell spawn of her and put her back in the tank...i have treated both tanks with prazi pro in the last month...i don't want to do that again, how should i treat?