Like Werewolves they have a mate they are destined for. They can sense each other and basically smell something 'heavenly' as their mates scent. Alphas all have two mates to choose from. Once a Alpha rejects a mate, the rejected mate is given another to be destined with. If a mate rejects the other they still feel the bond. Mates feel protective and slightly controlling over one another, but very sweet. They can't harm one another, their bond won't let them.