Their habit of driving away predators from near their nests is believed to encourage other birds such as orioles, doves, pigeons, babblers, and especially bulbuls, to nest in the vicinity.
In one study 18 of 40 nests had red-vented bulbuls nesting within 10 metres (33 ft).
An abnormal case of interspecific feeding with a red-vented bulbul feeding the chicks of a black drongo at their nest has been recorded.

They are so aggressive that they may sometimes land on large birds of prey and peck them when mobbing.
It has been suggested that the Asian drongo-cuckoo (Surniculus lugubris) has evolved to mimic this species.
The intensity of mobbing predators was studied in Java and observations showed that there was a significant increase in mobbing, during the nesting season, of some predators such as the Javan hawk-eagle but the black eagle, a nest predator is mobbed with equal intensity in all seasons.
It has been suggested that this strategy may avoid giving away the location of nests during the breeding season.
Their habit of driving away predators from near their nests is believed to encourage other birds such as orioles, doves, pigeons, babblers, and especially bulbuls, to nest in the vicinity. In one study 18 of 40 nests had red-vented bulbuls nesting within 10 metres (33 ft). An abnormal case of interspecific feeding with a red-vented bulbul feeding the chicks of a black drongo at their nest has been recorded.
They are so aggressive that they may sometimes land on large birds of prey and peck them when mobbing. It has been suggested that the Asian drongo-cuckoo (Surniculus lugubris) has evolved to mimic this species. The intensity of mobbing predators was studied in Java and observations showed that there was a significant increase in mobbing, during the nesting season, of some predators such as the Javan hawk-eagle but the black eagle, a nest predator is mobbed with equal intensity in all seasons. It has been suggested that this strategy may avoid giving away the location of nests during the breeding season.
Black drongo