how do reindeer fly

Reindeer don't actually fly, they simply glide through the air with the help of their magical antlers and the magical harnesses that connect them to Santa's sleigh. The antlers are enchanted with a special power that allows the reindeer to harness the wind and air currents to glide smoothly through the sky, while the harnesses are enchanted to make the sleigh as light as possible. So while it may look like the reindeer are flying, they're actually just gliding on air currents and using the harnesses to guide the sleigh.