The term 'microfauna' literally translates to “small animals”, and refers to small arthropods, such as springtails and isopods (a.k.a. roly-polies, pill bugs, wood louse). These invertebrates serve several important functions in the home vivaria: they act as tank janitors, helping to break down dead plant matter and uneaten food. They also provide the vivarium inhabitants with an extra in-house snack and aid in nutrient cycling.
Springtails are an excellent insect to add to a vivarium and we outline the care needed below.
Springtails are most commonly housed in plastic shoebox-sized containers outside the vivarium, although they can be kept in a variety of containers. The key is to select a container that is not completely airtight, allowing the culture to 'breathe'.

Springtail cultures should contain 3-4 inches of charcoal, with about 1 inch of distilled, reverse osmosis, or dechlorinated water on the bottom.
There are many different options for springtail substrate, with charcoal or coconut fiber being the most common. I prefer small chunk charcoal, with pieces being approximately 1/2 an inch long. The charcoal is washed to remove dust, then it is added to the container at a depth of 3-4 inches. Dechlorinated, reverse osmosis, or distilled water is added to a depth of 1 inch.
As with bedding, opinions vary greatly concerning what to feed your springtails. At Josh's Frogs, we exclusively use Spring to Life Springtail Food.
Dart frog keepers have used mushrooms (both fresh and dried), fish food, vegetable scraps, and dog food with success. We've found that grain-based foods (such as dog food and bread) tend to attract mites, which will overrun the culture and eventually cause its downfall. We have never had a mite issue while feeding Spring to Life Springtail Food.

The springtails will not be eating the actual food placed in the culture but will feed mainly on the mold that grows on it. With Spring to Life, the mold forms a low-growing mat that allows us to go several weeks between feedings.
One of the benefits of using charcoal as a springtail culture substrate is the ease in removing springtails from the culture. Springtails tend to float, while saturated charcoal does not. Add additional distilled, dechlorinated, or reverse osmosis water to the springtail culture, and simply pour the springtails floating atop the water directly into the vivarium. It's that simple, and a lot less hassle than other methods!
Once in the vivarium, target-feeding springtails can help maintain a healthy and thriving population. Feeding Josh's Frogs Clean Up Crew Cuisine every few weeks will help ensure you always have springtails in the vivarium.
Due to their small size, springtails do not break the surface tension of the water, and therefore float, making it easy to pour springtails out of a culture with a charcoal substrate.
Springtails (Collembola), although not necessary to successfully keeping dart frogs, certainly make proper husbandry easier. They play an important function in the home vivaria – mainly as nutrient cyclers and an additional food source. They are simple to keep and culture at home.
Check out this video on culturing springtails: