To safeguard their eggs and nestlings, Diamond Firetails are often recorded building their nests into the base of the large stick-nest of a bird of prey, such as a Whistling Kite, White-bellied Sea-Eagle, Wedge-tailed Eagle, Brown Falcon, Nankeen Kestrel or a Square-tailed Kite. One nest of a Whistling Kite contained nine Diamond Firetail nests! Others choose to build their nests among the prickly foliage of shrubs such as hakeas, rose bushes, boxthorn and the sharp-sounding Sea Urchin Hakea, a deterrent against all but the most thick-skinned predators.