Water does not run out of a dropper unless its rubber bulb is pressed. Explain the reason

Water does not run out of a dropper unless its rubber bulb is pressed.

Explanation:

The pressure inside the dropper is same as the atmospheric pressure when the rubber bulb is not pressed.

We know liquid only flows from a region of higher pressure to a region of lower pressure. Now since the pressure outside the dropper is same as that inside it the liquid does not come out.

But when we press the rubber bulb the pressure inside the dropper increases and hence the water flows out.