What Does “A Movement of Moles” Mean?
“Movement” most plausibly references the visible, constant evidence of mole activity aboveground, the molehills that appear scattered across a lawn or field as moles tunnel just beneath the surface. Each molehill is soil pushed up and out as a mole excavates a new section of tunnel, and a heavily active mole territory can produce a genuinely striking number of these mounds in a surprisingly short time.
Moles are remarkably efficient diggers, capable of tunneling through soil at a notable pace, powered by an unusually high metabolism that requires them to eat frequently, often several times their own body weight in earthworms and other invertebrates over the course of a week, just to sustain the energy their constant digging demands. “Movement,” in this light, describes both the mole’s literal underground activity and the visible aftermath left scattered across the surface above.
Example: “A fresh movement of moles had reshaped the entire back lawn overnight, new molehills scattered from fence to fence.”
Related: Collective Nouns for Mammals