I went away for the weekend and I had a friend take care of the tank. I came back to see my blue tang on the floor of my qt dead. I took it out and found a bunch of tiny bug looking creatures crawling all on it. Is this a parasite that killed it or were these creatures just feasting on the dead body? I have a yellow tang in the qt with it so I want to find out what it is asap to make sure I don’t put the yellow in any danger. I attached a video below of these creatures. I appreciate any input.