Most Muppets are controlled by one or more Muppeteers. It may appear simple at first -- just put your hand inside the Muppet's head and bring your thumb and the rest of your hand together to make the Muppet "talk." But how do you make a Muppet talk while using his hands? What about when Muppets interact with people?
In reality, operating a Muppet can be very complicated. During the run of "The Muppet Show," Muppeteer Dave Goelz, who had no previous experience in puppetry, admitted that "It takes maybe five years to do everything without thinking about it. In fact, I still find it difficult." Frank Oz stated that "What we are doing is so complicated that you don't really have time to think about how you are doing it [...] First your body understands, and then your mind grasps what you're doing. Sometimes" [source: Finch].
A hand-and-rod Muppet, like Grover of "Sesame Street," is one of the simplest Muppets to operate. The Muppeteer's right hand fits up through Grover's body to his head, and his hands are attached to rods that the Muppeteer can move and lift with his left hand. Most Muppets are left-handed because the Muppeteer's right hand is busy operating the head. The Muppet can clap or hug with both hand rods in the Muppeteer's left hand. Otherwise, an additional Muppeteer can operate the right-hand rod and the leg rods when necessary.
Ernie is a live-hand Muppet that requires two Muppeteers: one to operate his head and left hand and another to operate his right hand (known as right-handing).
Some Muppets are completely operated by rods and cables, like Rizzo the Rat. He has multiple rods to move his head, mouth, arms and legs. Slimey the Worm, at nearly 3 inches long, is so small that he is operated by a single rod. Some small Muppets, like the Doozers on "Fraggle Rock," are operated entirely by remote control.