Researchers at the MIT Department of engineering wanted to study the best ways to burrow through granular material. And in order to study the phenomenon, they looked at snakes, lizards, roundworms, and clams — and made some amazing videos, that it's hard to look away from.

According to the paper, Strategies for Locomotion in Granular Media, there are "fundamental principles underlying digging and burrowing strategies employed by biological systems." I'm sure this is true. I'm also sure there are "digging regimes . . . based on dimensionless digger size and the dimensionless inertial number." But what I really want to see the "biological organisms" used to represent the regimes. Above we see a nematode making its way through first a dense, then a partially cleared forest of glass beads. Below, we see a digger that isn't as mobile as a roundworm. The razor clam digs down from a fixed position.

And just to finish off the series, let's watch both a lizard and a snake sinuously make their ways through sand.

[Source: Beneath Our Feet: Strategies for Locomotion in Granular Media.]