Worm castings are also known as "Black Gold" in the terrarium world.  Mixing these castings in your substrate will ignite it with the nutrients it needs to create the perfect ecosystem.
 
Benefits of Worm Castings:
MEGA MICROBES: Think of them as a superfood or pro-biotic for your soil.  The Enzymes and microbes enrich your soil and contain trace elements that the plants will grave.  With 7x the nitrogen, 5x the phosphorus and 5x the potassium of regular soil, castings will supercharge your ecosystem.
WATER WEIGHT:  Castings can hold 3x their weight in water.  This water retention helps prevent tunnel collapse from drying and will keep your plants and ants hydrated for longer.
DISEASE DETERRENT:  The nature of worm castings means it is made up of "hummus" (Meaning ground earth in latin).  The earthworm castings extract toxins from the soil as well as harmful fungi and bacteria.  This has the ability to reduce and even prevent disease outbreaks.
PH POWER: Castings will help stabalise your soil and its pH level.
 
Instructions:
 
Sprinkle a thin layer over the top of an existing setup once every 2 months.
 
New setups: Add 100ml of castings for every 2kg of soil.