The question below consists of a set of labeled sentences. Out of the four options given, select the most logical order of the sentences to form a coherent paragraph.

P. Honey ants are common in deserts and other arid climates around the world.

Q. They are part of the “worker” caste of honey ants.

R. Other castes include soldiers, who protect the colony from predators and the queen — usually is the mother of all other ants in the colony.

S. Only some honey ants become “living larders”.