It's not enough to knit sweaters for our children and grandchildren -- no.

Dexterous fingers need more. They need to knit something smaller, faster: They need to knit hats for cats.

What started as a lark -- and to honor the grandmother who taught her to knit -- has turned into steady work for Sara Thomas, author of "Cats in Hats: 30 Knit and Crochet Patterns for Your Kitty" (Running Press, March 2015).

Thomas hopes the book, with quick knitting and crochet patterns for hats that resemble a dinosaur, chicken, bunny, turkey, cupcake, extraterrestrial, banana, Santa, elf, lion, baby bear and more, will free up time so she can knit and crochet something else.

"As much as I love the cat hat, I do want to do other things," admits Thomas, of Nashville, Tennessee.

In 2009, Thomas launched her Etsy shop, Scooter Knits, with disparate handmade items, including one hand-knit kitty hat, which quickly sold.

She's been crocheting tiny hats for feline companions ever since.

In 2012, her biggest hat-selling year, that was 300 kitty chapeaus (the holiday hats sell best).

Thomas sometimes crocheted until 4 a.m. to fill the orders.

Hannah Milman, editorial director of crafts at Martha Stewart Living, isn't surprised.

This photo provided by Running Press and Quarto Inc., shows Dinosaur from the book, "Cats in Hats," published by Running Press. The book released on March 24, 2015. (Phil Wilkins/Running Press/Quarto, Inc. via AP)

"People love their pets -- it's 'the new baby.' So it's no wonder people want to create personalized, wearable gifts for their pets," Milman says.

"A large part of it is also social media ... Who doesn't love seeing cats or dogs on Instagram in cute homemade outfits or accessories?"

At least one of the patterns in the book -- the Happy Birthday Cat Hat pattern -- is free at Thomas' blog.

Her two cats, Dorothy and Sinclair, are first to try out her admittedly kitschy creations.

Dorothy has proved agreeable, but not Sinclair.

This photo provided by Running Press and Quarto Inc. shows I Heart You from the book, "Cats in Hats," published by Running Press. The book released on March 24, 2015. (Phil Wilkins/Running Press/Quarto, Inc. via AP)

"Sinclair does not enjoy modeling the hats. In fact, he likes to attack them," says Thomas.

A patterns book of hats for dogs isn't out of the question.

And Thomas also would like to rework her grandmother's vintage patterns for a book:

"She was a beautiful knitter who grew up in Germany, so I'd want to make the patterns era-appropriate."

But first?

Cowboy

She'll probably embark on a holiday-themed book that puts more cats in outlandish hats.

She has learned that hats for cats sell.