Question
rabbits one at a time.. digging holes in yard  shallow depth 5 to 6 in... how to stop them from doing it

Answer
The rabbit is trying to make a nest to raise young. Easiest solution is to fence them out of your yard. Don't bother wasting your time or money on repellents or trapping. Borrowing a neighbor's dog for a few days may help scare the rabbits away for a while.

http://icwdm.org/handbook/mammals/CottontailRabbits.asp