Here's why:
* Subject: The subject of a sentence is the person, place, or thing that performs the action of the verb.
* Verb: In this case, the verb is implied (likely "believe"). While the sentence doesn't explicitly state the verb, we understand it based on context.
* Subject-Verb Agreement: The subject and verb must agree in number (singular or plural). Since "herders" is plural, the implied verb would also be plural.
Therefore, "herders" is the subject because it performs the action of believing.