 " Extinction " was first aired on September 24 , 2003 , on UPN within the United States . It received a 2 @.@ 5 / 4 percent share of the television audience , meaning that it was seen by 2 @.@ 5 percent of all households , and 4 percent of all households watching television at the time of the broadcast . It was viewed by approximately four million viewers , making it the lowest viewed episode of season three at this point . 
