Every single day, thousands of planes take passengers all across the world for both long and short distance flights. Each plane is filled with hundreds of travelers hoping for an easy and comfortable flight to their destination. Little do they know, during the hour or hours that they’re flying thousands of feet in the air, the flight attendants are dealing with a number of issues they must discreetly attend to. According to the flight attendants of Reddit, there are several secrets passengers don’t know about flying.

Although most travelers now are opting for carry-on bags, the plane cargo is filled with luggage for the whole plane. Among this cargo are some body parts which certainly sounds inappropriate out of context, but they’re typically organ transplants being transferred to hospitals. Also, the next time you’re flying, keep in mind that the potable water tanks are rarely cleaned, so flight attendants recommend you don’t drink coffee or hot tea while traveling.