I've heard that springtails and isopods that live in the substrate of the vivarium are very important to the health of the frogs. The stomach contents of wild dart frogs has been shown to consist mostly of springtails. I think besides healthy fruit flies, it's important to give the frogs a varied diet that includes springtails and isopods. I have a springtail culture that is growing well, but isn't booming yet, so I've been hesitant to feed them to my frogs, however I did seed their vivariums with springtails (which I never see)
When I can no more stir my soul to move, and life is but the ashes of a fire
When I can but remember that my heart once used to live and love, long and aspire
Oh, be thou then the first, the one thou art, be thou the calling, before all answering love
And in me wake hope, fear, boundless desire.