Alcidians are very sociable beings. They exchange some of their essence by biting each other's hands (it creates an emotional link) with their extendable their claw-like fingernails. This is dangerous to any other species, for it can also drain the subject of most bodily fluids or infect them with an emotional link. For example: if the Alcidian burns itself, the other subject feels it as well. The same with thoughts and feelings. Eventually, the subject will be under the Alcidian's complete control, unless the link is broken by rendering both of them unconscious.