Rescued from truncation:
Still wondering why these animals would be digging...perhaps like some fox = species they were in the habit=20 of caching their prey...
Clearly, they wouldn't; their proportions make it pretty much impossible. "Digging" is instead meant in the biomechanical sense: the arrangement of lever arms and forces is similar in alvarezsaurids and in scratch-digging animals, both burrowing ones and ones that open termite mounds.