Not that Canadian-born Katz minds. ''I like to be anonymous,'' he confesses. ''It lets me play characters in my writing. I can play the nebbish or the intellectual going to a writers' festival. No one really knows what is a Danny Katz.'' He learned during his days as a stand-up comic, too, that he prefers sticking to the spotlight's edge, crafting funny lines in private rather than delivering them up on stage. ''I'd feel sick in my guts three or fours days leading up to every single gig.''

Similarly, playing the sly fly on the wall came in handy particularly writing his new novel for teenagers, S.C.U.M. - for Students Combined Underground Movement - a diary-styled account of a day in the school life of nerdy romantic Tom Zurbo-Goldblatt and his misfit mates and his inner turmoil in summoning the courage to ask the hot Sarah Zitzlaff to the bush dance.

''I'm a flagrant eavesdropper,'' admits Katz. ''I love to listen in when my son comes home or his mates are around, in a pathetic sneaky way … taking copious notes in my head. I just love their language and the rhythms of their language.'' While Katz credits his 15-year-old son Jordie for inspiring the book, he explains it was as much about getting his son to read - but also giving him a story that was relevant, that spoke to him and one he might enjoy.

''Reading [for Jordie] is schoolwork,'' says Katz. ''We kept buying books we thought would interest him and there was just nothing on the market. He wanted funny books about his world.

''He didn't want fantasy or adventure; he's not into Harry Potter or vampire zombie teenagers. He just wants the stuff like [the TV show] The Inbetweeners or [the movie] Superbad. He wanted funny books about real kids.''

The publisher's blurb might glibly describe the book as ''Adrian Mole goes to Summer Heights High'', but Katz, who admits to an obsession with high-school stories, says school life hasn't changed greatly over the years. It's as much his life attending a rough high school in Sydney on the page as his son's.

There's always the bully picking on the genetically feeble, the class clown desperate for a cheap laugh, the dorks, jocks and loser teachers, and boys thinking about girls. ''In early caveman high school, I reckon kids were going through the same thing.''

While S.C.U.M. taps into Tom's raging stream of consciousness - with all its lax grammar, scant punctuation and stunted vocab - the book avoids outright swearing and smut, preferring to mine teenagers' curiosity and fear of sex for laughs as well as their ageless love of toilet humour, poo-and-wee jokes included. It also eschews taking any ''hugging and learning'' approach, as Katz puts it, but touches on cyber bullying and racism.

This isn't the first occasion Katz has ventured into the school playground. His Little Lunch series is probably the best-known of his young children's fiction, enlivened by his wife Mitch Vane's illustrations. On this occasion, Katz has opted for a much grungier doodle-style, reminiscent of MTV animated series Beavis and Butt-Head, to accompany his foray into young adult writing. Originally Katz's own scrawls, the illustrations have been redrawn by artist Suren Perera for the book, and brought to life in a small animation.

So did Jordie like it? ''He read the book in three nights, which was unheard of,'' recalls a relieved Katz. ''It took him eight months to wade through To Kill a Mockingbird, so this was a miracle.''

Spurred by this and his own admission the book was the most effortless writing he's done, Katz has already completed a first draft of a sequel, set around year 12 muck-up day. ''It's a war zone start to finish.'' And after that? ''I'd love to keep going forever because it's just a day in the life and there's so much going on in a teenager's head.''