Chapter 13: Zenar Biology 2

Zenar males have both sexual organs and can shift their gender at will. There is no male higher up other than Brutes and Commanders, or Pack Leaders. If they ever become higher, they shift their gender. It is reasoned that the wombs of females, which are capable of conceiving life, is for the Zenars a place where they can shift cells together to rapidly mutate and adapt. Since Zenars never reproduce with each other, no one is ever going to try impregnating one, and they can just infect corpses or other people that being female and having better mutation and adaptation abilities is beneficial over having a male's mating part.