LOS ANGELES—Sometimes voice-over casting is so obvious that it doesn’t look much like work. Take the hiring of an actor for the title role in Cats & Dogs: The Revenge of Kitty Galore, a story about a cat who plans to avenge humiliation (the loss of her fur) at the hands of dogs and humans by driving dogs mad and then preying on unprotected humans. (The film opens Friday [July 30].) Who better to play a wild-eyed Sphynx cat bent on world domination than the Divine Miss M?

In an L.A. hotel room, Bette Midler says that although she loved the character, there’s an isolation to voice-over work that’s unappealing. But she says that the finished project was worth the wait, thanks to the skill of Canadian director Brad Peyton and his ability to get the most out of the dogs, cats, and birds that make up most of the live-action cast of the film.

“It is lonely because it is just you and a sketch of the character and some built-in scenes,” she says. “You are not working with the actors. It is just one long looping session. I was really curious about the process because when I started it was just a sketch, and as time went on, the background of the other characters became more filled in. But the real thrill is seeing the finished project. The fact that Brad could keep all the balls in the air and make all these little movies in one film was staggering to me. I couldn’t imagine how he did it, because he was working with live actors and animals. There is nothing harder than that. They look like they know what they are doing, but they are animals. The trainers spend most of their time going ”˜Stay, stay, stay.’ I have worked with animals before, and it is like, ”˜Oh, my God!’ He was working with animals and actors, which is quite similar, and then you throw in robots and cartoons and it all melds together, and yet you can’t figure out which is real and which isn’t after a while.”

It was also about timing, at which Midler excels, having created one of the more iconic combinations of comedy and music for her stage act. Once she could relate to the work, she found it was easier to find the beats.

“There are some parts for which musical timing is important. The phrasing had to work with the character. Once the mouth is moving, you have to phrase along with the character. If you listen to that, you can hear where you dropped a beat and where you rushed to catch up. I will say that the fact that I sang for a long time helped a lot with that. It didn’t help the character as much as it helped me get through the work.”

When Kitty Galore loses the hair that she believes to be her identity, she wreaks havoc. Midler, whose own red hair has been a calling card of sorts during her lengthy career, says she learned early on not to take things too seriously when it came to her hair. “A long time ago, when I was working in theatre at 19 or 20, one of the girls was famous because on the opening night she had tried to straighten her hair and it fell off. She didn’t blink. She just kept going and slapped on a piece [a wig] and gave the performance of her life. She went on to become a world-famous opera singer. But when it happened, I thought, ”˜Check that out.’ From then on, I would never even bother to worry about it. I would just look around, grab a piece, put it on, and go out.”

Although her character in Cats & Dogs is out to destroy the world as we know it, Midler appears to be more interested in making the world a better place, or at least the part of it that includes her adopted hometown of New York City. In 2007, she joined with the New York City department of parks and recreation in an effort to plant a million trees. That’s in addition to the work she does with a group she founded in 1995 called the New York Restoration Project.

“Thus far, we have planted 375,000 trees,” she says. “It [the New York Restoration Project] owns 55 community gardens where people in the community grow their own food, and we teach kids about the environment and nature. It has been fantastic, and one of the best experiences of my life.”