8oz culture with a ton of sptringtails! 
Springtails are tiny arthropods (1-4 mm) and are used as "Tank Cleanup Crews" in a terrarium, eating mold and waste. They also make a great supplemental food for your poison dart frogs, or other small animals. This 8oz culture houses springtails on a charcoal, which can be added directly to your vivarium!
When you add springtails to your tanks they will reproduce. Simply dump the entire springtail culture in your terrarium and mix the substrate (springtails and all) in the springtail culture right into your substrate.