What is this, a treadmill for ants? (Yes, yes it is.)
As excuses go for not hitting the gym, not having equipment small enough for your species is about as good as it gets. Still, any ants reading this that want to get in shape should start planning a trip to Ulm University in Germany, where scientists have developed a teeny-tiny treadmill custom built for desert ants.
Of course, the actual purpose of the treadmill isn’t to help ants gain that buff segmented body they’ve always dreamed of – as good a use of research funding as that would be – it’s actually to help scientists understand how their legs move, and how they change their gait when searching for their nest.
That’s a bit more complex than your standard human treadmill, as you might imagine, with the equipment needing to compensate for stopping and changes in direction. To that end, what you’re looking at is an air-suspended styrofoam ball sensitive enough to measure the tiny movement of six individual ant legs using optical mouse sensors. The ants themselves were tethered to the ball with tiny leashes made from the filament of dental floss glued to their backs.
This is what that looks like in action:
So, what did the researchers find? Initially, when the ants think they know where they’re going, they march in one direction in a determined manner – using navigation techniques that past studies had revealed (the position of the sun and step counting are two that we know of). Of course, on a treadmill ants will never actually hit the nest, and the researchers noticed that when the ants failed to find their nests, they would switch to “search mode”, where they slow down and move around in a looping pattern.
The round animal-treadmill model has been in use since the 1960s, but this is the first time it has been used on anything quite this small and delicate. While this treadmill was specifically designed for desert ants, it’s possible that the same kind of thinking could help us understand the way that smaller critters move when they think nobody’s watching.