"When I was a little kid, they said I was hyperactive, sent me down to a child guidance clinic." Sitting in the dressing room of Philadelphia's monstrous Spectrum, Van Halen vocalist David Lee Roth pushes back two feet of scraggly, dirty-blond hair from his hawk face.

"Every night after dinner, I'd start ticky tack on the table with a knife and fork, singing TV commercials, acting out cartoons. And my folks would say to the company, 'Don't mind Dave, he's just doing what we call Monkey Hour.'" Roth leans forward with a million-dollar smile, ready to punch the last with a gravelly growl that can barely contain its glee. "Well, I turned Monkey Hour into a career. I ticky tack and I sing and I dance and I tell jokes and 'm having a ball misbehavin.'"

Having a ball in the corporate rock world of Van Halen means selling millions of records and filling, 20,000-seat megatheaters like the Spectrum (three nights last week) and Capital Centre (tonight and tomorrow) with hard-core fans who believe in stereo sawbucks: $10 for tickets, another $10 for T-shirts, programs, patches and other rock paraphernalia. It's a serious business, with certain crew members assigned "chase the bootlegger" duty at each concert.

Van Halen, unlike most of the monster groups, has hit the top without much airplay and without the press. In fact, the group, and Roth in particular, have attracted some of the most vitriolic press since rock criticism was born. The feeling is summed up in a letter to Creem, the only national magazine devoted to hard rock and heavy metal. "I want to write for your magazine. I hate David Lee Roth. Do I qualify?" (The editors answered: "You and an astonishing number of our readers.")

Roth, a spandex-clad electric centaur whose on-stage leaps and erotic posing have blended with the group's maximum volume to turn Van Halen into America's Led Zeppelin, is unerringly described as "What Sylvia Miles would look like if she were a man," and "the female equivalent of Robert Plant." And these comments are from his fans. One girl did write saying, "Boy, would I love to have his hair." Roth sees a lot of the commentary as jealousy directed at the band's openly hedonistic and unabashedly affluent life style. Five years ago, the band was playing covers in Los Angeles singles bars; now they are all multimillionaires, surrounded by servants, bodyguards and other trappings of sudden success.

Interestingly, Van Halen has spent the last five years as if there were no tomorrows, meaning the pervasive pursuit of pleasure symbolized by Roth's unique paternity insurance arrangement with Lloyd's of London; he managed to convince them that debauchery was "instrumental" to his work. "This stuff happens all the time," Roth shrugs. "You get letters from all over saying, 'You did this, you did that, you're responsible for this . . . and I want money.' You've got to insure yourself against all kinds of things, much less paternity. There are so many good ways to be bad. That's why you've got to cover your behind."

Roth at 25 is not much different from the kid sneaking into the candy store after it's closed with the prospect of long hours with the goodies. "It becomes very difficult to deal with the distractions that come with the fame and the success and the fortune," he whimpers. "It's really difficult to deal with the hordes of 18- to 25-year-old women in sexy clothes who swamp you outside the hotel . . . the private jet planes . . . the catered buffets . . . the drugs that are everywhere -- not that I condone them. Everybody at the show is hysterical, it's 110 degrees and you feel like an animal up there until your head's gonna blow up like in 'Scanners.' It's difficult to deal with all that . . . but somehow we manage. It's tough, but somebody has to." Roth is all but rolling on the padded floor, convulsed with laughter.

Van Halen tends to make the news portion of radio more often than it gets airplay. There was the M&M riot in New Mexico where the band did thousands of dollars of damage to a hall when they were served brown M&Ms -- their contract said the brown ones had to be removed. There was the controversial bondage poster of Roth by photographer Helmut Newton. There was the recent marriage of guitarist Eddie Van Halen to television star Valerie Bertinelli. There was Roth's arrest in Cincinnati on the "serious" charge of "inciting the crowd to smoke cigarettes" (charges dropped). "

But mostly there is the derision leveled at the band -- lobotomy rock is one of the kinder terms -- and on Roth, whose singing does admittedly fall somewhere between a succession of Tarzan yells and the well-miked groans of a cow being branded over and over. Still, the band has millions of die-hard fans who snap up the records (its latest, "Fair Warning," is top 10) and crowd the arenas. "Maybe it's my triple spin with the knickerbocker break into the full splits with a smile on my face and the toes pointed perfectly," muses the acrobatic Roth before his pre-performance ritual of warm-up exercises and taping up of the legs (a program arranged by Los Angeles Lakers trainer Jack Kern). "It's just like playing ball; you've got to make your career last a little longer. And the music should look like it sounds," Roth insists."It's music 10 feet off the ground. Getting up there ain't hard; coming back down is the whole ball game."

Roth has little time for the critics, whom he once decried for liking Elvis Costello "because they all look like Costello. Critics take Van Halen very personally. I think one of the main reasons is that a lot of critics have children of their own. It frightens them to think that any of their kids could turn out like me or one of the other fine members of our band. But while they're busy typing away in the office and putting together these horrendous exposes and diatribes against Van Halen, their kids are at home in bed under the covers with a flashlight, a Van Halen concert program and a Walkman. I get 'em from all sides."