Patiently waiting for lunch to swim close.
Sometimes funny though, birds do scratch their bodies a lot. Mostly it is because of many ectoparasites. They also clean their bodies by either taking mud bath or preening their feathers. Picture below show two species, 1. Great Egret, and 2. Black-headed Ibis scratching their head.
The black drongo is a medium sized passerine bird and known for its extreme aggressive behaviour. It can even chase bigger birds such as kites and eagles. In few places it is also called as the “police bird” because of its behaviour.