Seldom have children’s writers covered their subject so completely. In fact, they’ve got the material down perfectly, from A to Z.

There’s always room for new, innovative alphabet books. Here are three that are conceptually creative.

“Mrs. McTats and her Houseful of Cats” (Aladdin Paperbacks, $6.99) will make kids scream with laughter, and parents – well, they’ll just scream. This insanely funny romp, by Alyssa Satin Capucilli with illustrations by Joan Rankin, presents a main character who takes in stray cats at an exponential rate.

The author’s multiple messages add up to an admirable result. Capucilli amazingly manages to make it an accurate counting book as she reels off cat names that materialize alphabetically.

These sly pusses, and the reader, get a sneaky surprise at the end. And each and every cat, thanks to Rankin, is a complete individual. It’s not hard to see why Mrs. McTats fell in love with them all.

Laughing and learning at the same time yield big benefits.

In “Found Alphabet: The Ordinary Becomes the Extraordinary” (Houghton Mifflin Co, $16), everyday objects are combined into photo collages that took quite a bit of thinking and composing.

Interestingly, just looking at the authors’ and illustrators’ names is enough to get a quick overview of letters: It is written by Ramon Shindler and Wojciech Graniczewski, with illustrations by Anita Andrezejewska and Andrzej Pilichowski-Ragno.

The “found” art (an octopus made of breadsticks and an orange, for example) is amusing and sometimes startling. The verses, although not quite as original as the illustrations, are jaunty and easily recitable.

A note from the creators explains that ordinary homey items inspired them because “we all live in the house of imagination.” The book offers readers shelter from the mundane.

“The Turn-Around, Upside-Down Alphabet Book” (Simon & and Schuster Books for Young Readers, $15.95) takes bright-hued letters in equally bright boxes and transforms them into all kinds of things with a mere sidewise movement of the volume.

Created by Lisa Campbell Ernst, this foray into shifting shapes causes readers to look long and hard at what letters can form, besides letters. An upside down “A” becomes “a drippy ice cream cone.” A straight-line capital “I” turns into “a three-layer cake” when viewed horizontally.

The candy colors will pull in kids; the concepts introduced will capture their parents’ interest as well. There is an invigorating sense of a puzzle unfolding.

These books do more than teach letters – they teach lessons about life at the same time. To come away from them is to know more about the world that letters are only a part of.