So virgin queens use this small pouch in their heads to transport a tiny amount of fungus from the mother colony to start their own new nest. They seed the new fungus garden from this pocket and so start the new colony.
Found this on the webpage http://link.springer.com/article/10.1007%2FBF02224744
The leaf-cutting ant Acromyrmex octospinosus was shown to filter out into its infrabuccal pocket from liquid food, particles down to ten μ in diameter. The pocket acted as a receptacle for material licked from the ants' fungus garden and from their own bodies, and for leaf wax licked from leaves used for fungus culture. The infrabuccal pellets of worker ants, which might contain contaminating fungal spores, were always found away from the fungus garden and mostly on the refuse dump. Virgin queens however, regurgitated their pellets onto the fungus garden. Pellets regurgitated by worker ants were streaked onto agar plates, and from these the ant fungus was cultured. Worker ants were not able to start a new fungus garden, but the use of the infrabuccal pocket by queens to transmit the ant fungus to newly founded colonies can be seen as part of a general behaviour pattern.
So all of the ants have infrabuccal pockets, they are generally used to store waste matter, but in queens these are used firstly to transport fungus and secondly to fertilise the fungus. Although it seems that you can grow fungus from the contents of the ants infrabuccal pockets, it was not possible for the worker ants to start new fungus using the contents of these pockets. All very interesting.
This is a view of the anatomy of a carpenter ant, not sure how this relates to LCA's but interesting none the less.
