Do you watch shows about nature? Think about what you saw. Sweeping landscapes? Exotic animals? Now try to remember what you heard. Insects buzzing? Pandas munching bamboo? Elephants stomping?

Did you really hear what you think you heard?

Documentary crews stay far from the animals they film. Otherwise, they’d spook the critters! Cameramen use telephoto lenses. These lenses capture tiny details from a long distance.

But there’s no “telephoto lens” for microphones. To capture the sounds of animals walking and eating, they would need to get close. Too close. If they did record, the sound would get muddled. They would pick up chatter from the film crew.

So what’s a documentarian to do? Most of them fake it.

Enter the Foley artists. Foley artists make sound effects for movies. They don’t record actual noises in the field. They create realistic noises in a studio. As they work, they watch footage on a monitor. They make sure their recreations match the video perfectly.

Think you hear a marching elephant? Thud, thud, thud. Foley artists create that heavy thump with rocks, straw, and dirt. A bird beating its wings to take flight? Foley artists wave a pair of worn leather gloves. Flap, flap, flap. Horses galloping over stone? That’s good old-fashioned coconut shells. Clop, clop, clop.

But it’s not all trickery. Animal cries and roars are complex—too complex for artists to fake. Documentaries might use real animal noise samples from “sound libraries.”

Foley art can change the way we think about animals. In real life, a slithering snake might be too quiet to hear. A Foley artist can make it sound sinister and threatening.

Next time you watch a nature documentary, listen closely. What are you really hearing?

Why? Not everything is as it seems. When we pay close attention, we notice things we may not have noticed before.