Trachycephalus resinifictrix is a phytotelm breeder: it uses water that collects in small plant-held containers, in this case cavities in canopy branches and trunks. A male calls from inside the hole, and the cavity acts as a resonating chamber that carries the low hollow call through the forest. Females deposit eggs on the water surface inside.
A tree hole is a demanding nursery. Volume is small, oxygen can be low, food is scarce, and drought or an overflow can end the brood. Tadpoles feed on detritus and on eggs deposited into the pool, and are tolerant of poor water quality. Breeding in the canopy removes the risks of fish and most aquatic predators, and of the exposed journey to a pond.
The name comes from the defensive secretion. Disturbed frogs exude a sticky white fluid from the skin, which is distasteful and can irritate mucous membranes. The species is not milk-producing in any sense, and the secretion is a chemical defence common in the genus rather than something unique to it.