1. Casting begins more than a year in advance for each season.

2. A private investigator is involved in the casting process. In an interview with Betches, contestant Darius Feaster said, "The P.I. was asking me about my friends’ histories based on pictures from social media."

3. All contestants must undergo STD screenings — and the most common reason why hopefuls don't make it is because they have herpes.

4. They also have to take a comprehensive psychological exam before appearing on the show.

5. And they usually only find out that they've been selected to appear on the show about two to three weeks before filming begins.