Is it possible to be invisible?

Being invisible is useful for animals that spend a lot of time in places with no good hiding spots, like the air or open ocean, says Kate Feller. She studies vision and behavior at Union College in Schenectady, N.Y. The secret to invisibility is all about light. “The way we see things is when light is reflected back off of an object onto our eyes,” says Feller. The more light that can pass through something undisturbed, the harder it is to see that thing.