Tropical White Springtails | Collembola

Size: 375ml

All things you apply to a terrarium will be subjected to high amounts of moisture and warmth leading to faster decay, especially right after the terrarium has been made. The reason for this is that at the beginning of the terrarium's life, the materials inside are much more volatile from the sudden introduction of constant moisture and warmth which is the perfect location for decomposition to start, and for mould to thrive.

A springtail's main food source is mould arising from decomposing matter. Just like all life, mould's goal is to reach the fruiting stage and spread its spores. Springtails being present will actively keep mould from maturing and is an excellent way to stop manual intervention in a terrarium.
The reason manual intervention to stop mould is riskier is that you may be unknowingly spreading mould by opening the lid and rushing air in, or by disturbing clusters when attempting to remove the mould.
As mould takes in oxygen and releases carbondioxide, mould in large amounts will reduce the total oxygen in a terrarium and has the potential to increase the temperature with increased CO2 amount. Low oxygen levels can also kill other terrarium life through asphyxiation.

Springtails in reduced oxygen and higher heat will reduce average springtail size as heat requires a higher metabolic rate and favours smaller life. Springtails can reduce their overall size by up to 30% if required by moulting back to back but over a long period of time in a closed ecosystem, springtails will not be given the chance to get to such a size.

Springtails also eat fungus and have the potential to clean up root rot as root rot is not actually rotting of the root but a fungus growing around the root, suffocating the plant.

Feeding springtails by adding your own food inside your terrarium is not necessary and may only increase mould amounts and potentially ruin aesthetics and damage moss & plants.

 Source: https://www.microgreening.com.au/blog/all-about-springtails-a-comprehensive-guide