This story originally appeared on BusinessInsider.com.
The world's busiest airports see anywhere from 55 to 100 million passengers pass through in a year.
When you deal with even a fraction of these busy travellers from around the world on a daily basis, you can expect to encounter some bizarre human behavior.
As one flight attendant told Business Insider, you really get to see it all: "Never say never. Weirdness will always outdo itself if you challenge it."
Still, there are some things that would stun even the most seasoned airline employee.
Here are some of the most trying work conditions airline workers including flight attendants, gate agents, ticket agents, and other airport customer service reps have been subjected to:
"Yoga people trying to use our galley as their personal studio" is one of the weirdest things a flight attendant with four years of experience told Business Insider they've seen.
Strange announcement requests
A flight attendant with three years of experience told Business Insider that she's gotten her fair share of strange announcement requests.
"One gentleman was angry, and he asked me if I could make an announcement over the PA. When I asked him what he wanted me to announce, he said, 'Somebody in this vicinity is passing gas, and I need them to stop,'" she said.
Another passenger asked her to make an announcement asking a neighboring passenger to give up the armrest.
"The weirdest thing was hosting Michael Jackson in our employee break room so he didn't have to sit in the terminal," an anonymous airline customer service agent told Business Insider.
People who make soup with the airline water
In response to the Quora question "What are the weirdest things flight attendants have seen in their line of duty?" former flight attendant Heather Wilde said she's seen her fair share of things many people would consider weird.
Among the strangest were people who made soup using the airline water. "Guys, the water lines haven't ever been cleaned — ever," she said.
Dirty diapers in the seat
“I saw an elderly lady chase a ticket agent while swinging her cane as a club trying to hit the agent,” a retired airline customer service agent with 21 years of experience told Business Insider.
Adult temper tantrums
"I saw a grown man in his late 40's fling himself down on the lobby floor for a full-fledged temper tantrum that would make a two-year-old proud," a retired airline customer service agent with 21 years of experience told Business Insider.
"A passenger stood on top of the closed toilet and defecated," a flight attendant with 30 years of experience told Business Insider.
Spiders on a plane
Missing security blankets
"An irate businessman who had delayed luggage once told me the real reason he was irate was because he couldn't sleep without his blanket," a retired airline customer service agent with 21 years of experience told Business Insider.
Packing everything, including the kitchen sink
“A customer once actually showed up with a kitchen sink to check in on his flight,” an airline customer service agent with 30 years of experience told Business Insider.
"One of the weirdest things I experienced was clear-air turbulence. I was bounced between the ceiling and the floor twice and broke my foot in two places when the bar cart landed on it," a flight attendant with 27 years of experience told Business Insider.
"A customer tried to bring a baby kangaroo on the plane as a service animal," a retired airline customer service agent with 18 years of experience told Business Insider.
"Many years ago, I opened the door on an inbound aircraft to find the flight attendant wide-eyed and freaked out by the urine streaming down the side of her face," an airline customer service agent with 18 years of experience told Business Insider. "A passenger with dementia had mistaken the intercom cubby for a urinal, and she had grabbed the soaked handset to make the arrival announcements."
From streaking down the aisle totally nude to falling like an axed tree, when passengers consume an unfortunate mix of Ambien — which people sometimes take to sleep on planes — and airplane cocktails, it makes even the most normal people do very bizarre things, writes a flight attendant with the pen name Betty in her online series "Confessions of a Fed-Up Flight Attendant."
"These folks are sleeping, which means they think they are at home and safe in their beds. When they are home and safe in their beds they think it is perfectly acceptable to take off all of their clothes," Betty writes.
Alas, this is not acceptable behavior on a long-haul international flight.
A severe fear of flying
"I had a woman run to the front of the plane and throw herself in my closet. (She thought she was going to bathroom.) She then curled up in the fetal position in the closet and started sucking her thumb. She later told me that she forgot to take her anxiety medicine before flight," a flight attendant with 30 years of experience told Business Insider.
The worst place to put a baby
States of undress
"One passenger attempted to board the plane wearing a raincoat and no pants," a flight attendant with 40 years of experience told Business Insider.
"A passenger stole a sandwich off the galley counter. It was a crew member's, who bought it at the airport. They'd taken a bite and left it on the counter (with a little lipstick around the bite mark) to assist someone. When the crew member came back to the galley, it was gone," a flight attendant with 21 years of experience told Business Insider.
"The crew member later found the thief eating it at their seat," the flight attendant continued. "When asked how they could just take a used sandwich with lipstick on it, they shrugged and said, 'I was hungry.'"
A bloody mess
"I haven't seen this, but I did have flight attendants tell me about blood dripping from the overhead because someone was bringing in a goat's head from a Caribbean island. That was before TSA and all their security procedures were put in place, of course," Annette Long, a flight attendant with 13 years of experience, told Business Insider.
"I was checking in a lady for a flight, and she told me she had a dead baby in her bag," an anonymous airline customer service agent told Business Insider.
"As it turns out, it wasn't a dead baby — it was the remains of a dog, properly cremated and correctly contained," the agent said. "But she only told us this after we looked in the bag. A dead dog is not a baby. Don't tell me you have a dead baby in your bag!"
Just plain rude behavior
"Someone threw a soda at me because of an over-sold flight," an airline customer service agent with 18 years of experience told Business Insider.