Who doesn't love to snuggle up with a little kid and a copy of "Goodnight Moon," or "Llama, Llama Red Pajama"? These classic books with their bold images and silly prose help kids fall in love with reading. But while these books have a place in the evening bedtime ritual, experts say we should also be reading kids more challenging books with vocabulary and syntax that they might not learn without a little help.

In a recent post on Quartz, Doug Lemov, author of "Teach like a Champion" and co-author of "Reading Reconsidered: A Practical Guide to Rigorous Literacy," argues that once kids have learned to read basic books on their own, we should continue reading to them — but with books that stretch their imaginations and their vocabulary.

The obvious benefit to reading kids harder books is that it will introduce them to words they won't come across in the average Dr. Seuss book.

Even though they were already excellent readers on their own, I read "The Evolution of Calpurnia Tate" with each of my daughters when they were around 9 years old. In just the first chapter of the book, we came across the words "quadroon," "interlude," "pestiferous," "chivvied," "torrid" and "ponderously." These are words we don't use in casual conversations, so it was a great way to expose them to new vocabulary without them having to look up each word in the dictionary as they went along.

Challenging texts also tend to use more metaphors and similes — figures of speech that might go over the heads of younger readers. But when you read these books with kids, you can help explain the meaning behind the prose so when they come across these literary techniques on their own, they'll understand.

"Hearing complex syntax read aloud builds an affinity for a different kind of vocabulary," wrote Lemov in TES, a British forum for educators.

Finally, reading harder texts to kids will introduce them to a plethora of topics — some happy, some sad — in a safe environment where they can ask questions and proceed at their own pace.

Of course, there are still lots of great reasons to read fun, silly books to kids. But don't forget to leave time for the more complex books too. The silly books are wonderful for helping kids learn to love reading, but it's the more challenging books that will make them readers for life.