I have let my furries dig in a rice box since they were babies.  Luckily,
none of them seem to be interested in eating the rice...just digging and
throwing and snorkeling.  It has been said that as long as it is uncooked
and NOT instant rice, there isn't enough time for their digestive systems
to break down the rice in terms of it expanding inside of them.  If mine
have eaten rice, which I'm sure at least a grain or two has been
swallowed, I've never encountered any digestive troubles from it.
 
Good luck,
Angela
[Posted in FML issue 4168]