Not fungal, but cool science nonetheless (plus, ants are important in some fungal symbioses). Walter R. Tschinkel uses plaster to study ant nests (particularly the Florida harvester ant, Pogonomyrmex badius) and his recent article in Bioone provides us an interesting insight into any colony morphology. Check it out.
Ants, fungi, and bacteria
I have to admit that I am fascinated by co-evolution of symbiotic and mutalistic systems. A review by Richard Robinson gives an overview. A great example is the mutalism between ants and fungi where the ants cultivate the fungi for food. There are more layers to the relationship as a fungal parasite (Escovopsis) attacks the cultivated fungi, and a bacteria. Several researchers have studied the coevolution of these studies including Ulrich Mueller and Cameron Currie. Currie and Mueller have published several great studies describing the patterns of coevolution and the nature of the cooperation.