Every autumn, kids in th United States and beyond start getting really excited about a single date: October 31st.

I wonder why?

No I don't.

It's Halloween, of course.

A special day for dressing up, eating candy, and sometimes getting scared on purpose.

It's a curious combination.

So how did thi annual celebration come to be?

Why do we dress up in costumes for Halloween?

Halloween has its roots in ancient festivals in Northern Europe.

These festivals marked the harvest and the changing of the seasons.

As late fall turned into winter, cold and darkness would begin to descend.

Celebrations at this time of year marked not only the dying of the year, but people who had passed on as well.

Many cultures believed that this changing of the seasons was a time when the boundaries between the living and the dead were more fluid than normal.

So they might dress in costumes to scare spirits away, or leave treats on their doorsteps to keep spirits happy outside the home, rather than in.

Other cultures have similar traditions that involve honoring and remembering the dead.

As with many modern holidays, there's an element of religion involved too.

As Christianity spread through Europe and later to other continents.

The church incorporate many of these older traditions into newer Christian ones.

In this case, they called the celebration of the Dead on November 1st.

All Hallows and October 31st became Hallows Eve Halloween for short.

When Europeans came to North America, they brought these traditions along with them.

In the United States, the name Halloween stuck.

And in Mexico, the celebration mixed with other traditions that were already in place and became known as Dia de Los Muertos: the Day of the Dead.

By the early 1900s, in the US, candy makers had caught on and started making candy just for Halloween.

Thus, trick or treating spread in popularity.

For most people, Halloween is no longer a religious holiday.

It's just a fun time for kids and adults to put on a costume, eat your favorite candy, and spend time with friends.

Trick or treat.