Elmo, Big Bird, and Mr. Snuffleupagus aren’t just puppets to fans of Sesame Street: They’re vibrant characters who are every bit as real as the beloved series' human actors. It may look effortless, but bringing foam, fur, and feathers to life is a skill that takes years to master. WIRED asked five Sesame Street puppeteers to share the secrets behind the craft in a new video.

Different puppets rely on different mechanics to function. Big Bird and Mr. Snuffleupagus, for example, consist of puppeteers (two in Snuffy's case) wearing full-body suits, while smaller characters like Elmo and Abby Cadabby have single puppeteers with one hand inside the head moving the mouth and another controlling rods attached to the arms. Some puppets have eyelids that move up and down. For puppets without this feature, puppeteers have to come up with creative ways to express emotion. Elmo puppeteer Ryan Dillon pulls a wooden handle in Elmo’s head when he wants to give the character a puzzled look.

Translating hand movements into convincing facial expressions is tricky, but one of the biggest challenges the crew faces is space. Next time you see four or five Sesame Street puppets in the frame at once, try picturing that same number of full-grown adults rolling across the floor beneath them.

For the full interviews with the puppeteers, check out the video below.

[h/t WIRED]