Love it! Just wait until it's deep enough all you see is his head sticking out of the hole. We have one spot that is allowed for digging in the back yard, that is directly under the picnic table (this is so no one falls in and gets hurt). it's gotten pretty deep at times and fill it in now and then. When I sit at the table my feet just hang there and have to spin around to get up off the bench.
It's amusing at times to find things from the past that have been hidden by dogs of the past. We've had dogs digging in that hole for about 40 years!!! They all think it is their own personal dog den.