Faris' ears go back slightly, though he is not too gravely offended by the comparison. She's only comparing it to what she knows. "Those that harm the host are not symbionts but parasites. A symbiont both benefits and gives in return. The K'da are such a species. Before six Earth hours pass, we must rest upon the surface of a suitable host's skin as a two-dimensional form. It is comparable in appearance to the human art form of tattoo."