Who says Las Vegas is strictly an adult playground? Disney on Ice and the Doodlebops made stops earlier this year. Elmo and the Sesame Street crew are coming in April. And the Wiggles, the colorful preschool kings from Down Under, pop up Tuesday at the Thomas & Mack Center . Joining the Wiggles on their "Racing to the Rainbow Live!" tour are Captain Feathersword, Dorothy the Dinosaur, Henry the Octopus, Wags the Dog and the Wiggly Dancers. The Wiggles are one of the top-grossing entertainment groups in the world. The group was founded in 1988 in Sydney, Australia, by Murray Cook, Anthony Field, Jeff Fatt and Greg Page. Page left the group last year for medical reasons and was replaced by Sam Moran. During a recent phone interview from Sydney, Cook - the Red Wiggle - talked about the group's past, present and future. Q. How did the Wiggles begin? It was Anthony's idea (Blue Wiggle). We were teachers. He was into children's music and said let's record an album for children, which we did, and we got it released. We thought it was just a hobby, but it started to sell and we started doing some little shows - preschools, birthday parties and things like that. It just got bigger and bigger, and we decided to give up our teaching and give it a go for a year. It just kept going. What's the goal of the show? Mainly for children to have fun. But with our background in children's education, we know children can learn more when they're having fun. "Can you point your finger and do the twist" is learning about body movement. "Fruit Salad, Yummy, Yummy" is all about eating healthfully, but the way to present it is not, "Don't eat candy," but a more positive spin: Fruit salad is yummy. There are definite elements of education in there, but it's really subtle. To what do you attribute your amazing success? I suppose some of it is just our background. The original Wiggles were early childhood teachers, so we studied about the way children think and how to use music with young children. We knew how to talk to children, not to talk down to them but to talk to them on their level. And the songs are catchy, which the kids are into. And there is a lot of chemistry between the members of the group - with most successful bands, the chemistry between the members comes across. We were all friends before we started. And families respond to that fact that we are genuine about what we do. There are quite a few different elements. How has Greg's leaving affected the group? Has it been a difficult transition? It's been relatively smooth. It's always hard to lose someone whose been with you for 15 years. It's hard for us personally, he's a friend of ours and we miss him on the road and everything and the audience misses him, but there's a lot of goodwill surrounding what we do, with our audience, and they're pretty welcoming. We did a tour in Australia before the end of the year, and a lot of people had signs up saying, "Welcome, Sam." So I think that's really helped him, helped his confidence, and yeah, he's a different singer, a different performer than Greg, but we say there's a bit of a rebirth really, and it's been going along pretty well. What is Greg's problem? The diagnosis is orthostatic intolerance. I believe it means his brain doesn't tell his heart to pump more blood like when he stands up or runs or moves around, so he wasn't getting enough blood going through his body and he would pass out or feel faint. Is it curable? It's not. He's just learned to manage it. He's not doing great. He's up and down. Your home base is Australia. How much time do you spend in the United States? We come to the States about three times a year. We spend about four months a year in the U.S. Are you as popular here as in Australia? I think we're getting to be, here in the U.S. I think we're more popular in Australia just because we've been there for so long. But in terms of numbers, the United States is certainly our biggest country, just because you have 15 times our population. Have children changed in the 15 or 16 years since the Wiggles began? Kids are kids. There is a difference between the older kids in Australia and America. There are definitely some cultural differences. But I think children at the age we are reaching, the preschool age, there are not a lot of differences. I don't think children over the years have changed that much. What about performing in non-English speaking countries? It's difficult when performing for children. You need them to understand what you're saying. So yes, we do mostly go to English-speaking countries. One thing we're trying out is localized versions of the Wiggles. We started it in Taiwan, where we did a Mandarin-speaking Wiggles. Another one will be in South America. I believe it will air pretty soon now. We've been to Asia a few times. In China, the kids didn't know anything about us, but they got up and danced when we played the music. Has the show changed over the years? Our live show has changed. As we've become more successful we've been able to put more money back into the production so it looks better. We can take more people on the road. Everything evolves in different ways. We get ideas for songs or we try something different as we go along. Sometimes we do more dancing, sometimes more playing of instruments. It's always evolving. It's a way of keeping it fresh for us, but it's also important to keep it fresh for the audiences as well. Are you yet playing for children of the children you started performing for 15 years ago? Not quite, but we're pretty close, in Australia certainly. We have a lot of 18- and 19-year-old fans, which makes us feel a little bit old, really. Other than the Wiggles, are you into anything else? No. This is our whole life. We do more than 200 performances a year, and we put out two or three DVDs a year. We're always writing songs and recording, and we do TV as well - we're on the Disney Channel in the States. We're pretty busy. What's in your future? We're always looking for new challenges. A few years ago we did a feature film, something we might like to explore in the future, but mostly we just work on different ideas for the show. We'll keep going for quite a while. We're still young - youngish.