Biomimicry is a great tool to solve problems. Rather than reinvent the wheel, we can often look at the solutions that nature has come up with over millions of years of trials & errors. For example, the study of how ants can so quickly move underground and dig relatively stable tunnels in all kinds of soil can teach scientists and engineers a lot, some of which might be quite useful to make robots that could do search & rescue missions or explore hard to access corners of the Earth (equipped with the proper sensors, they could be used for all kinds of environmental monitoring jobs).
That's exactly what researchers from the Georgia Institute of Technology have done.
Dr Nick Gravish, who led the research, designed "scientific grade ant farms" - allowing the ants to dig through sand trapped between two plates of glass, so every tunnel and every movement could be viewed and filmed.
"These ants would move at very high speeds," he explained, "and if you slowed down the motion, (you could see) it wasn't graceful movement - they have many slips and falls." (source)
Some of the things that they learned are that ants use their antennae to catch themselves when falling, and that they are very deliberate about the diameter of the tunnels that they dig, keeping them all the same size regardless of soil type (approximately one body length in diameter).
Check out some of the very interesting research videos published by Dr Nick Gravish:
The researchers even built a "homemade X-Ray CT scanner" to look at tunnels in 3D: