Holes on plugs in North and Central America

Two flat prongs you see on standard plugs used in North and Central America make sense.  

But how about those holes near the tips? 

They're not always there, but there's a good reason manufacturers put them on plugs. 

Thanks to these holes, the outlet grips the plug more firmly. This way, it doesn't fall out. There are small, lined-up bumpers inside most outlets. 

 

 

They fit perfectly inside the holes on plugs. It's a win-win situation: the prongs are safe inside the outlet. But with enough force, you can still remove the plug. 

The second thing about the holes is that they allow you to wire electric power directly to the prongs. In this case, you don't even have to use an electrical outlet. Also, you can put a locking mechanism or bar through the prongs. This way, no one will be able to plug the device into an outlet. 

 

 

Holes on pen caps

Some pens have caps with holes in their tops. 

Those are put there as a safety measure; if someone accidentally swallows a cap while chewing on it, they'll still have some space to breathe. 

 

 

Holes on Airplane windows

Airplane windows have tiny holes, which might make you nervous when you see them. 

But they're essential, and a plane needs them to fly safely.  

These holes protect you from the difference in pressure outside and inside the cabin.

When you order a soda to go, it usually comes with a plastic lid; this lid is practical when you're in the car or walking and want to prevent your soda from spilling. 

But it can also be a great coaster! Just flip the lid upside down and place it under your cup. 

 

 

Door handles made of brass or copper.

Most doorknobs are made of brass and other copper alloys, and it's not accidental. 

These materials are known to be self-disinfecting, and Thanks to these antimicrobial properties, bacteria don't spread as much as possible.  

 

 

The different number on sides of cosmetic products

Different numbers are often put on the sides of many cosmetic products.  

These numbers aren't picked randomly; they tell you how long your product will last.  

This way, you won't put it on your skin after it expires. 

 

 

Brushes on escalators

Those escalator brushes can clean shoes pretty well, huh? But they're made for safety reasons. 

When people are on an escalator, brushes keep them away from the sides. And this prevents bags and clothes from getting stuck.  

Holes on spaghetti spoons

Most spaghetti spoons have a hole in the middle. 

Such a hole can be pretty helpful when you scoop some pasta and need to drain it. But it's also a great measuring tool! 

The hole fits precisely one serving of pasta. 

 

 

The drawer below the oven

Some ovens have a little drawer at the bottom. At first sight, it's perfect for storing pots, pans, and trays. A couple of extra points for creativity if you use it this way!  

But it's not the drawer's primary purpose. It's designed to keep the food you've just cooked warm while you're waiting for lunch. 

 

 

Tabs on the sides of the box of aluminum foil

When you take a box of aluminum foil, pay attention to the tabs on the sides. You can press them in, and they'll keep the foil straight and prevent it from rolling.  

 

Hole on the soda can tab

Aaah, nothing better than a cold soda drink on a hot day. Soda cans come with a small tab that helps you quickly open the beverage. 

But the hole in the tab also has its purpose; that's where you can put your straw to stop it from floating up to the surface.