An action verb with a direct object is transitive<span> while an action verb with no direct object is </span>intransitive<span>. Some verbs, such as arrive, go, lie, sneeze, sit, and die, are always </span>intransitive<span>; it is impossible for a direct object to follow.</span>
I am pretty sure it is because they thought they where not big enough to fight him so they where afraid...