Trivia: While giving a lecture at the Hollywood Scriptwriting Institute, director Joe Dante trash talked the novel "The Howling" on which the movie is based. One person in the audience raised his hand and asked, "So, you don't like the book, huh?" with Joe stating, "No, not really." The man responded that he was the one who wrote the novel. To Joe's surprise, the man in the audience was Gray Brandner, the author of "The Howling."
Trivia: Many shortcuts had to be taken due to the incredibly tight budget. For example, the infamous final shot of the sex-scene being hand-drawn animation was done because the crew ran out of time and money and couldn't get the shot done in live-action. Additionally, Karen's final transformation was not seen, and her transformed face is only seen in extreme closeup because the effects crew ran out of money and could only afford to make a small puppet head for the scene.
Trivia: The man who is sitting on the couch with his wife watching the werewolf transformation on the news broadcast is a cameo from Mick Garris, director of such films as "Critters 2" and "Psycho IV: The Beginning." He also directed "Making a Monster Movie: Inside 'The Howling'".
Trivia: The gentleman that enters the phone booth as Karen White leave I is low-budget film Guru Roger Corman.
Trivia: There are numerous Easter-eggs relating to wolves throughout the film. For example, in one scene a character is eating "Wolf" brand canned chili. And in another scene, a character is reading a book written by author Thomas Wolfe. There are many other small wolf references scattered throughout the film. Keep an eye out for them.
Answer: I think they were purposely brought there to both join the colony. Marsha, who desired Bill, was impatient and bit him. As for not being mad at her, the Colony was slowly turning to her leadership, instead of the Doctor's compassion treatment.
Why would the colony want Bill and Karen to join them?