Narrow bridged musk turtle hatchling, Nebok digging the sands

Nebok, my narrow bridged musk turtle hatchling, is digging the sands. What he wants? I thought he wanted to make more space for him passing through. One of my friends, the owners of narrow bridged musk turtle, told that he might be trying to find some foods in the sands by digging the sands. I think his opinion seems reasonable.