10 things you didn't know ancient Egyptians invented

Prosthetics are likely to have been first thought up by ancient Egyptians. Scientists believe that an artificial toe found on the foot of an Egyptian mummy buried near Luxor is likely to be the world's oldest prosthetic body part.

Carved out of wood, this toe would have been tied onto a foot or directly onto a sandal. The prosthetic is currently housed at the Egyptian Museum in Cairo.

There is evidence that suggests that condoms were used in ancient Egypt as far back as 1000 BC. Sheaths made of linen were used not as a form of birth control, but as protection against diseases and ... insects! 

The oldest known formula for toothpaste was scribbled on a piece of papyrus nearly 1500 years ago.

Because of the coarseness of their bread, which wore out their enamel, ancient Egyptians had to take extra care of their teeth. This meant rubbing a mixture of rock salt, mint, dried iris flower and pepper on their teeth to keep them strong and healthy.  

Ancient Egyptians, keeping your possessions and family safe since (at least) 2000 B.C.! 

The oldest lock we've found was unearthed from the ruins of an ancient Egyptian palace. So a big thanks goes out to the ancient Egyptians for their invention of the door lock! And a not so big thanks for starting the problem of lost keys.  

Bad breath, caused by rampant gum and tooth infections, was a major problem that plighted Egyptians back in the day. Enter mints!

Made from frankincense, myrrh, cinnamon, and honey mixed well and shaped into pellets. 

No, it wasn't da Vinci, as some suggest. The earliest known pair of scissors were in fact made in Egypt, around 1500 B.C. They were made from two bronze blades connected by a metal strip. Squeezing the handle would make the blades cross paths cutting whatever was in their way.  

The Egyptians organized their calendar based on the farming seasons of Akhet (the flooding season), Peret (the sowing season), and Shemu (the harvesting season). 

They divided each season into 4 months, each month consisting of 30 days. Months were split into three 10 day periods, with the last 2 days of each period acting as a sort of weekend.

Finally, they would add 5 days at the end of the year, to harmonize it with the solar cycle. 

It's not entirely clear who started using the comb first, but what's certain is that ancient Egyptian women, the rich ones at least, used elaborately carved combs, hairpins, razors and hand held metal mirrors.  

Many believe the ancient Egyptians were the first known civilization to organize labor. During the reign of Ramses III, workers went on strike because they did not receive their payment on time. Demands for better treatment were eventually met, making this the first known strike in history.

Also, and contrary to popular belief, the Pyramids weren't built by slaves. They were built by paid laborers.  

Maybe not one of the most important additions to our planet, but cosmetics have grown into a multibillion dollar industry. In ancient Egypt, both men and women used make up as a form of beautification and for religious purposes. Although it remains a mystery as to which ancient culture first developed cosmetics, in ancient Egypt Kohl was applied to the eyes with a small stick on both the upper and lower eyelids with a line extending from the corner of the eye to the sides of the face. Eye brows too were painted black.