Attacks on pedestrians by roving “rat packs” of teen-agers have occurred at least 10 times in the past month, Berkeley police said. The attackers do not appear to be organized gangs but are simply impromptu groups “out for kicks,” Police Inspector Jim Gaebe said. He said male and female victims of various ages have been assaulted all over the city. A Berkeley man was fatally injured Sept. 10. Gaebe said that most of the attacks have been on weekends and that in at least three cases articles of clothing were taken.