Jenny Harris, of Balclutha Primary School, asks :-
How does a dust bath clean a chicken's feathers?
Christine Thomson, an anatomist at Massey University's Institute of Veterinary, Animal and Biomedical Sciences, responded.
Feathers are extraordinary structures being both light but strong. They serve to keep the bird warm, protect its skin, and of course, enable it to fly. But just like our clothes, feathers get dirty. Feathers also make a warm, dark environment in which parasites love to live. Parasites irritate the bird; imagine how it feels to have insects crawling around in your hair.
Feathers require ongoing care by the bird to keep them clean and functional. Preening involves nibbling or stroking the feathers with the beak, and is critical for keeping the plumage in order and oiled. Birds have an oil-secreting gland (uropygial gland) at the base of the tail, from which they will collect oil with their beaks and then distribute that through the feathers. Bathing is often a prelude to preening and some birds use water for this. Other birds like to wriggle and flap around in dust and this is often followed by the bird shaking itself thoroughly and then preening.
Dust is thought to pick up sticky, particulate material in the feathers. When it falls out, it carries the debris with it, thereby cleaning the feathers. Additionally, dust may help to get rid of parasites, such as tiny flies and mites that are crawling around in the bird’s feathers.
Some birds may also ‘ant’ themselves. This involves either sitting on an ant mound and letting the ants crawl over them, or picking ants up in the bill and wiping their bodies with them. Ants produce a pungent chemical called formic acid and this may help to repel the parasites chemically. But then again, birds may also bathe and ant, just because it feels good.
Many animals like to roll in sand or dirt to keep the flies and insects away from them and also to help dry off after exercise or being wet. A roll in deep sand is often included as part of horse stables.