Rats in the Trees

''Street'' literature too often degenerates into the obvious — preachy laments about soulless kids and their drug-wasted environment. So these short stories, which present a nuanced portrait of a prepubescent Oakland skate-punk gang, are all the more devastating for their superficial casualness. Now being reissued after the success of Jess Mowry's 1992 novel, Way Past Cool, Rats in the Trees treats normality both as an occasional incursion (''I hope all the shootin' get done before school start'') and as foundation: The Oakland kids perform the same cocky/frightened balancing act as the suburban ''squids'' they despise, only they do so in a place where it's easier to get an Uzi than a box of matches. As one youth counselor says, ''This ain't Sesame Street.'' But then again, Sesame Street isn't real. B+