Cartoonist Stephan Pastis may be best known for his 15-year-old syndicated comic strip, Pearls Before Swine, which runs in 750 newspapers worldwide. Yet his notoriety may be shifting thanks to his popular middle grade book series based around kid detective Timmy Failure, which debuted in 2013. The father of two recently saw the sixth book in the series, Timmy Failure: The Cat Stole My Pants, published last month by Somerville-based Candlewick Press, and talked creativity, comics, and cats with us.

How did you make the leap from daily cartoon strip to childrenís chapter book?
I was approached by a book agent whose mother was a fan of the comic strip. He asked if I would be interested in writing a book for middle graders. I thought it sounded like a lot of fun, so I said yes.

And how do you juggle the workload?
I write 10 strips a week, instead of the required 7. This buys me 19 free weeks a year to do other things, including taking about two months off in the summer to write the next Timmy book. I love it. Itís a great break from the strip.

How did you come up with the idea for Timmy? Did you think of the character first and develop his role as detective later, or did the idea of a kid detective come first and you created Timmy from that?
The latter. I liked the idea of a kid detective who was not smart and could not solve anything. It made me laugh. It seemed so different than other kid detective characters.

How has Timmy changed over the series? Or has he?
I think in each book he learns a little. But not much. He is a slow learner.

What do you want readers to take away from The Cat Stole My Pants? (Other than the fact that cats are ďremorseless criminals,Ē as you wrote, which is obviously true. Thank you for getting that in print.)
Ha, ha...well, thank you. I want them to laugh! Thatís always my goal.

What advice do you have for parents of children who love to draw and want to encourage their child to continue?
Oh, man, to encourage it! Creativity just unlocks the brain! Itís a great outlet.

You previously sat on the board of the Charles Schultz Museum. What was that experience like, and how did Schultz influence you? Did you ever get to meet him?
Yes. His strip was why I began to like comic strips and why I wanted to become a cartoonist. His simple art style, his pacing, his characters, his tone, all influenced me and countless others. Yes, I met him three times. It was the thrill of my life.

The introduction of Timmyís Dad in this latest book struck me as bittersweet and yet hopeful at the same time. It added a level of reality to the book that I didnít expect. How did you make the decision to introduce his father? Were you always planning to introduce him at some point in the series or was this a new idea?
I think itís always been leading up to that. Timmy has a hole in his life, caused in large part by the absence of his father. I think thatís why there is a Total [Timmyís polar-bear sidekick]. He fills that gap. So, at some point, I wanted to introduce the father.