Those holes in airplane windows help maintain the cabin pressure
You must have seen a hole in the window if you have ever traveled by plane. Did it give you the creeps? Of course, it can be frightening at first because you are flying through the air, and you begin to wonder if it is due to air pressure or something else. Window panes, believe it or not, are designed to keep us safe.
They are called “bleed holes” or “breather holes’ because they help planes maintain a constant air pressure when they travel to cruising altitudes of up to 33,000 feet. Due to high altitudes, air pressure and oxygen levels drop. So the plane can deal with the changing cabin pressure thanks to the breather hole since it helps the pressure to stay at a safe and comfortable level.