Since Santa Claus treats every living thing with equal respect, when Santa picks out reindeer, he doesn’t pay attention to their gender or sex. He is only concerned with their job-related qualities and character as role models for children. So if they are nice and kind, and if they are really strong fliers with big hearts that know how to get a tough job done on time, Santa Claus is happy to have them on the team!
There is some talk that only female reindeer have antlers, and that is generally true. But, in the case of reindeer empowered to fly at high speed in the dark, antlers have proven to be important for balance and safety… So, when the Reindeer get their magical flying powers on Christmas Eve, all of them have a full set of antlers to keep things running smoothly on the long journey.