Antedeans found spaceflight extremely traumatic and survived the ordeal by entering a self-induced catatonic state. Upon arrival at the end of a voyage, Antedeans required great quantities of food, known as vermicula to replenish their bodies. Few Humans saw an Antedean in the flesh. Antedeans had unsophisticated minds that were highly susceptible to telepathic reading by Betazoids; Worf considered them to be "a handsome race," whereas Lwaxana Troi stated that the "last time [she] saw something like that it was being served on a plate."
In 2365, the USS Enterprise-D escorted two Antedean dignitaries from Antede III to a conference on planet Pacifica. Here the Antedeans were to be given an opportunity to join the Federation. However, immediately prior to transport down to Pacifica it was revealed, by Ambassador Troi, that they were in fact assassins and their robes were lined with ultritium. They had planned on blowing up the entire conference. (TNG: "Manhunt")