I attempt to introduce springtails into all of my vivariums before adding the frogs. They are a great food source, but sometimes the darts make quick work of them. I don't know if Mantellas go for them as much, but they are still a good critter to have in the soil. They will do best if you have a lot of leaf litter.
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Patty
Pahsimeroi, Idaho

Dendrobates: auratus blue, auratus Ancon Hill, tinctorius azureus, leucomelas. Phyllobates: vittatus, terribilis, lugubris. Epipedobates: anthonyi tricolor pasaje. Ranitomeya fantastica, imitator, reticulata. Adelphobates castaneoticus, galactonotus. Oophagia pumilio Bastimentos. (updated systematic nomenclature)