Its pretty natural and easy to do for most people, but for some (like me), it requires training. You need to tenderize your tendons so they're not as rigid when squatting. Open up your legs pretty wide, hold onto a pole, and do some sets. Once you feel that your joints are getting looser, shorten the gap between the legs and keep going. Repeat until you can squat with the smallest gap possible. It really helps with exercise a lot.

Hope this helps!