As a rule the temper of a camel is very good; the driver guiding it by ropes fixed by string to a stud, very similar in every way to a collar stud, which is put through the nostril of the beast, and a tug at this, with an accompanying word of command, such as "Hooshta," when it is wanted to lie down, is generally sufficient inducement to make it do what it is told.
Source: wiktionary