Sometimes als will bury themselves if it gets too hot. The rubbing can sometimes be indicative of a mite infection and the digging and restless behavior could also indicate discomfort. Even females that have not mated will often lay infertile eggs so she could also be looking for a place to lay. I'd check your temps, take the lizard out and do a thorough inspection for mites and spend some time watching her in the cage to see if you see anything crawling on her and make sure that there is a moist hidebox available in which she can lay her eggs. Soetimes they will also rub on furnishings when they are preparing to shed.

-Alice