?Halloween season has arrived in the United States This curious celebration of the macabre has origins in ancient pagan Europe, but it has become a $6.5 billion US industry, mostly from candy and costume sales. As part of Halloween, "haunted house" attractions are set up every year in major cities, including Houston.

There is something in human psychology that makes people enjoy being scared.

During Halloween season for the past 26 years, thrill seekers in Houston have come to Screamworld and paid good money to be terrified.

Having things jump out at you in the dark does the trick.

Having a creepy setting also heightens the anticipation of what could come next.

Screamworld owner and operator Jim Fetterly designed every part of the attraction to frighten his customers.

"If you can catch a person off guard for a split second, you can get them (scare them) really good and people like that," Fetterly said.

Screamworld includes some mechanical devices, but Fetterly says humans can be much more frightening.

"You must have good actors. They are the ones who have the high-impact scares that the customers crave," Fetterly said.

For that, Screamworld employs dozens of people to play zombies, maniacs and monsters.

Most of the actors are either students or have other jobs during the day, so they have little time to get ready before the attraction opens.

Chris White, who works in IT by day, directs the make up team.

"We basically have about two hours to get 50 to 75 people made up," White said.

The transformation can be stunning. But the actors also employ skill and experience.

"If you ever took choir or singing, you are taught to use your diaphragm and not strain your vocal cords. (In character) You are already dead!," said one man dressed as a zombie.

"You have to put yourself in that mindset - my parents are dead, I probably killed them," said a girl with bloody face makeup.

Actor Tristan Baldwin says his wall-climbing zombie role has helped him land roles in horror movies.

"To develop a character every night actually helps me with my acting career, so I am building up something - 'Hey, I have been a zombie for five years,'" Baldwin said.

But the actors and owner Jim Fetterly have less than two months each year to cash in on Screamworld's seasonal appeal.

"I tell you it is crazy because you base your whole livelihood on what you can make in six weeks," Fetterly said.

But he and his cast are also in this business for the thrill of thrilling others.

?Halloween season has arrived in the United States This curious celebration of the macabre has origins in ancient pagan Europe, but it has become a $6.5 billion US industry, mostly from candy and costume sales. As part of Halloween, "haunted house" attractions are set up every year in major cities, including Houston.

There is something in human psychology that makes people enjoy being scared.

During Halloween season for the past 26 years, thrill seekers in Houston have come to Screamworld and paid good money to be terrified.

Having things jump out at you in the dark does the trick.

Having a creepy setting also heightens the anticipation of what could come next.

Screamworld owner and operator Jim Fetterly designed every part of the attraction to frighten his customers.

"If you can catch a person off guard for a split second, you can get them (scare them) really good and people like that," Fetterly said.

Screamworld includes some mechanical devices, but Fetterly says humans can be much more frightening.

"You must have good actors. They are the ones who have the high-impact scares that the customers crave," Fetterly said.

For that, Screamworld employs dozens of people to play zombies, maniacs and monsters.

Most of the actors are either students or have other jobs during the day, so they have little time to get ready before the attraction opens.

Chris White, who works in IT by day, directs the make up team.

"We basically have about two hours to get 50 to 75 people made up," White said.

The transformation can be stunning. But the actors also employ skill and experience.

"If you ever took choir or singing, you are taught to use your diaphragm and not strain your vocal cords. (In character) You are already dead!," said one man dressed as a zombie.

"You have to put yourself in that mindset - my parents are dead, I probably killed them," said a girl with bloody face makeup.

Actor Tristan Baldwin says his wall-climbing zombie role has helped him land roles in horror movies.

"To develop a character every night actually helps me with my acting career, so I am building up something - 'Hey, I have been a zombie for five years,'" Baldwin said.

But the actors and owner Jim Fetterly have less than two months each year to cash in on Screamworld's seasonal appeal.

"I tell you it is crazy because you base your whole livelihood on what you can make in six weeks," Fetterly said.

But he and his cast are also in this business for the thrill of thrilling others.