For most of us, we don’t spend a whole lot of time considering how we get our mail or who delivers it every day. It comes, we’re happy, and we move on with our lives.

Given recent debates about how essential the service actually is, though, we thought some education might be in order – and here are 10 things you might not (but might like to) know about the U.S. postal service.

10. They have good reason to be wary of your dog.

In 2014, 5767 postal employees were attacked by dogs, with Los Angeles bringing home the dubious award for the most bites in the nation.

Mail carriers are instructed to use their bags to protect their bodies, though many also choose to carry mace for their own protection.

9. The mailboxes weren’t always blue.

They began painting them a uniform blue in 1971.

Prior to that, the color of boxes varied from a drab olive green to different shades of blue.

8. Several famous people began their working lives as mail carriers.

Walt Disney, William Faulkner, Steve Carrell, and many others carried mail before they became household names.

7. They have their owns stamp cave.

SubTropolis is a sprawling excavated limestone mine in Kansas City, Missouri.

The caves are home to many companies, and the USPS finds them an idea hub for stamp storage and distribution.

6. And a team to decipher the worst handwriting.

The Remote Encoding Center in Salt Lake City, Utah receives all of the mail that’s deemed impossible to read at a local level.

There are 1000 workers there to decode and solve the mystery – in an average of four seconds, which is insane!

5. The longest route in the nation is nearly 200 miles.

Sidney, Montana has the longest rural delivery and mail route – it’s 190.7 miles long.

4. The shortest is under 3 miles.

In Parker, Colorado, the carrier only has to travel 2.3 miles every day, and the carrier in Carrollton, Texas, only has to go 1.2 miles a day.

3. Some post is still delivered by mule.

Every day in the Grand Canyon, mule trains deliver around 4000 pounds of mail, food, supplies, and furniture to the village of Supai.

2. They also employ boats.

In Michigan, a 45-foot mailboat called the J.W. Westcott II delivers mail to ships passing on the Detroit River.

The post office has a legal obligation to deliver mail to all Americans. Boats also deliver mail on Alabama’s Magnolia River.

1. It’s part of the Constitution.

Benjamin Franklin was the country’s first Postmaster General, and when the Constitution was ratified in 1789, part of it gave Congress the ability to “establish post offices and post roads.”

In 1792, President Washington signed the Postal Service Act, which created the Post Office Department.

Today, it employs more than 7.3 million people.

I have to admit, I either didn’t know these things, or I never really considered them until now – and I always love knowing more!