I am 100% certain Kate DiCamillo knows that owls eat rats and that's one of the reasons I love her second "Orris and Timble" book, about an owl and a rat who are friends.

The new one, "Orris and Timble: Lost and Found," has something to say about how good friendships can withstand being tested — not, in this instance, because one of the friends wants to eat the other but because they briefly fall out of touch and there are some hurt feelings and it's not immediately clear if those hurt feelings can be overcome.

It's a deceptively simple book, at 76 pages, about half of which are lovely paintings by Carmen Mok, who also illustrated "Orris and Timble: The Beginning." Like many DiCamillo books (which include Newbery Medal winners "The Tale of Despereaux" and "Flora & Ulysses"), "Orris" sees the mutual value in cross-generational friendships: Orris the rat, we are told, is old and Timble the owl is young. In "Beginning," Orris had more of a mentor role but the new book finds Timble exploring the world and telling his buddy about what he sees.

Even better, "Orris and Timble" insists that folks who seem to have little in common — even those who are, as Orris notes, "natural enemies" — can respect and like each other. That's a message that we don't hear enough in our current, off-with-their-metaphorical-heads age.

The creatures in "Orris" seem to be alone in the world (the elderly rat spends a fair amount of time chatting with a cartoon character on a tin of sardines who, occasionally, seems to answer him). They're also probably lonely, since they manage to get over that natural-enemies hurdle. But DiCamillo's book is careful to distinguish between pleasurable moments of solitude and loneliness.

Orris experiences the former when he contemplates Mok's lovely sunset, but the latter in Mok's finest illustration, a beauty in which Orris expresses his hurty feelings by hiding from Timble behind a pile of his beloved books, with only his wounded side-eye to let us know he longs to reach out to his long-absent friend.

Orris and Timble: Lost and Found

DiCamillo's elegant language, with its repetitions and gentle rhythm, feels almost like a high-and -lonesome bluegrass song:

"Do you want me to tell you a story?" said Orris to Timble.

"Actually," said the owl, "I thought I would tell you a story."

"Really?" said Orris.

"Yes," said Timble. "It's a story about an owl. It's a story about an owl who got lost."

All kinds of children will read "Orris and Timble: Lost and Found," bringing to it a variety of beliefs. But I really like the idea that all of them will be reading a book that says friendship can surmount differences, can even be enriched by them. And that, while it's true that occasionally we all lose our way, it is also true that it's possible for those of us who are lost to find our way back.

Orris and Timble: Lost and Found

By: Kate DiCamillo.

Publisher: Candlewick, 76 pages.

Event: 2 p.m. May 3, HarMar Barnes & Noble, 2100 N. Snelling Av., Roseville. Free.