The mass breeding of insects for animal protein production could compete efficiently with conventional livestock to feed the ever-growing human population. Insect excrement (frass) is one of the main outputs of this process. In a recent review, scientist Poveda highlighted the benefits of reusing frass as bio-fertilizer in agriculture. Insect frass provides soils with nutrients, beneficial microorganisms and different biomolecules of great interest. Therefore it promotes plant growth and increases crop productivity for a sustainable agriculture.