Most travelers check into a motel or hotel, toss their bags on the bed, and collapse without thinking twice. But seasoned hotel workers, security staff, and even medical professionals say there’s one simple step that could protect you from a night you will never forget — and it starts with the bathroom light.

For years, guests wondered why so many frequent travelers sleep with the bathroom light on and the door slightly open. It isn’t superstition. It isn’t fear of the dark. And it’s not about creating a cozy glow. According to multiple longtime hotel staff members, this small habit can prevent some of the most common — and unsettling — nighttime dangers that happen in unfamiliar rooms.

The biggest reason? Pest activity. Roaches and other insects are notoriously active in the dark, especially in older motels or high-traffic rooms. A dim bathroom light draws them away from the bed area and keeps them moving toward moisture instead of crawling anywhere near you while you sleep.

But that’s not the only concern.

Guests have reported waking up disoriented in pitch-black rooms, tripping over luggage, hitting furniture, or even walking straight into walls. Hotels rearrange layouts, move furniture during cleaning, and the absolute darkness can feel disorienting even to calm travelers. A soft bathroom light prevents accidental injuries that happen more often than people realize.

There’s also a safety factor most travelers never think about:
If someone were to enter the room by mistake — whether a drunk guest with the wrong key, or a staff member who wasn’t updated about occupancy — a lit bathroom is one of the first signs the room is not empty. It has stopped more intrusions than most people would ever imagine.

In the end, such a small habit makes all the difference:
A single light can protect your night, your safety, and your peace of mind.

Travelers who swear by this rule say once you understand why…it becomes impossible to sleep any other way.