HiRISE observations like this one are used to aid in classification and volume estimates of dunes in the USGS global dune database.
Sand dunes are among the most widespread aeolian features present on Mars. Their spatial distribution and morphology are sensitive to subtle shifts in wind circulation patterns and wind strengths. These provide clues to the sedimentary history of the surrounding terrain.
What's fascinating about this image is the ridges running the length of the dunes here, creating the spectacular illusion that we're looking at millipedes. This is a good example of what's called "pareidolia," where we see things that really are not there.
Luckily, the power of HiRISE helps us see formations in greater detail to know we're seeing impressive dune ridge formations and not insects!
Photo credit: NASA/JPL/University of Arizona
Note: The location of these dunes is in the region west of the Hellespontus Montes, southeast of Rabe Crater.