The female went for two weeks without eating. She tried to dig, but did not have sufficient mucus to stabilize the sand. Also, my male was starting to try to dig suggesting an approaching molt. I became that I might lose both, so I decided that I couldn't wait to construct a cut away burrow. I got a 3 foot piece of 4" pvc and attached a 45 degree elbow to each end and placed it in a 100 gal tank on top of a 5 '' sand bed. The female, which was already in this tank, entered the pipe immediately. There is no sand in the burrow, but she did managed to mold some sand around the entrance. The next day she ate.
Today I decided to add the male. He entered immediately and there was no aggression. WIthin a few minutes he was looking out one end, she the other. Within half an hour, both took food. I'm not sure, but I think the male offered his shrimp to the female. This would be typical behavior in the field. Since then, the male has been furiously trying to close the entrance with a sand - mucus cap while the female is in the middle of the burrow. I see no signs of trouble, so hopefully they will live happily together. I may still try to build the cut away burrow, but for now I will leave them in peace.
Roy
