Why does people's ears feel like they need to pop wen they go to the mountains?
Because there is a drop in pressure when you gain altitude and this causes gases to expand and the feeling like your ears need to pop to equalize the pressure.
Yup. It's air pressure. That's why I always chew gum when taking off or landing in a plane.
It has to do with air pressure. Whenever there is a big difference between the air pressure inside your ears and outside your ears the ear drum expands or contracts to try to even out the pressure. This causes the popping effect in ones ear.
Air pressure in ear canal
The pressure makes your ears pop