rifle through

昨日は会社を休んで初めてテニスの試合に出ましたが、結果はさんざんなものでした。
さて、Zoobiquityを読んでいます。
Grooming's powerful calming effect applies as much to solo as to social cleaning rituals. Cats and rabbits may spend up to a third of their waking hours fastidiously licking themselves. Sea lions and seals spend many hours a day rifling through their own fur. Birds roll in dirt, fluff preen, and pick with their beaks. Snakes, lacking napkins or hands with which to wield them, often finish a meal by wiping their faces against the ground.
"rifling through" は文脈からすると、毛づくろいをすることだと思いますが、辞書で確認します。
・Merriam-Webster's Online Dictionary: to search through something quickly and carelessly often in order to take or steal something: He rifled through the papers on his desk.
・Macmillan Dictionary: rifle or rifle through to search quickly through something such as a container or a group of objects in order to find or steal something: She rifled through her closet looking for the dress.
・American Heritage Dictionary: To search (an area or container, for example) thoroughly, especially using the hands with the intent to steal or remove something: rifled the desk, looking for the keys.
寄生虫や汚れを取るために探すと言うことでしょうか？