This is a carpenter ant sniffing. That’s how they follow the chemical trails that are laid by fellow ants — or research scientists. Of course, ants don’t have noses. Their smelling organs are mostly in their antennae. They have a few on their feet, but that’s another story. Smelling is how they navigate the world. It’s how they recognize other ants and locate food. It’s more important than sight, sound or even touch. Scientists wanted to find out more about exactly how ants follow a scent. So they painted tiny trails with ant pheromones and added ink so they would be visible. The ants, as expected, could follow various routes, like zigzags, dotted lines and curves. Sometimes, they just wandered off. Researchers analyzed dozens of hours of footage using various computer models that tracked the ants’ body positions and antennae movements. What they found was that ants use their antennae to sweep the trail side to side the way you might use a metal detector. And they weren’t one-trick ponies — or ants. They adopted three strategies to navigate their environment. First, there was probing. When an ant was still or moving slowly, it kept its antennae close to each other. There was exploratory. Ants took slow, winding paths near a trail with antennae further apart. And, when they had the trail down pat, there was trail following. They moved along the trail accurately, antennae on either side of the path. Interestingly, each ant seemed to have a left-right antenna preference. They kept one closer to the trail. Some were lefties. Some were righties. And when an antenna was removed, many ants adopted new strategies for navigation, changing their body position and antennae range. They definitely weren’t automatons. You might almost say they had personality.