Why can camels walk on the sand?

well, they have fat storage in their hump so they don't get hungry. they're also native to the Arabian desert and it's climate so obviously it will be easy for them to walk in such hot and arid conditions.

In terms of the actual walking, the hoof is incredibly wide and gives the camel a lot of traction because of the increased contact area. That allows them to push through sand that would not give traction to humans.