Robert,
    Here is easiest method I know of to end the food digging problem.  Buy
one of those plastic food storage containers with a top( I find the round
ones work best) cut a pie wedge shape in the lid.  Secure the lid to the
bottom by punching holes and twist tying on ,also punch holes in container
and secure to the cage.  That's it.  They can stick their little fuzzy heads
in to eat but seem to lose interest in digging.  Hope it works for you.
Sorry no help on the litter mine usually stop playing in it when I leave
some of their old poops behind.
                                                Corrie
                               Peanut,Lucy,Satchmo,Bandit and Flea
[Posted in FML issue 1356]