The human body is completely and totally insane when you think about it. Thanks to Reddit, we've collected some of the creepiest facts about this bag of bones that we all call a body. Enjoy!

Every so often I remember that cysts can sometimes contain hair and/or teeth and then become incredibly uncomfortable. -spicytotino

Human beings are a cesspool of bacteria and when you die your body eats itself from the inside out. -FukU6050

The brain will always/usually try to ensure its survival, if knocking you out does so, then you will faint for the safety of the brain. -SonicBoom500

The way your eyes are shaped causes your vision to be upside down but your brain flips the image automatically. -Ryand118

A dead body will often move as its being cremated. Muscles contract as they cook, after all. Sometimes this means a body will sit up in the crematory machine. -Corgi_with_stilts

Fallopian tubes are mobile and active parts of your reproductive tract. When one tube isn't there or is “broken” the other tube can actually move over to the opposite ovary and “pick up” an available egg. -quacker1982

Viewed from a medical standpoint, the inside of your gastrointestinal tract is technically the outside of your body, making you a meat donut. -DrPCox85

Allegedly, your immune system has no clue your eyes exist. Effective tomorrow, if your immune system found out about your eyes it would treat them as a external threat. Therefore try and neutralize your eyes leaving you blind. -e_faulkk05

If you get a splinter or foreign object stuck in your skin you can hold a flashlight against your skin and shine the light through your flesh, and the foreign object will be a dark spot. Light actually passes through our flesh quite well. Also, if you shine a bright enough light into your mouth you can see the light in your own eyes. -SuperBaconjam

A pregnant female corpse will build up enough gas to expel the fetus even after death. Look up coffin birth. -TeamWaffleStomp

Your intestines "know" what shape they're supposed to be in, and can move themselves, which means gut surgeons can just stuff them back into you when they're done and they'll sort themselves out. -SnowDemonAkuma

Human skin is overlaid with a pattern called Blaschko’s Lines, stripes covering the body from head to toe. The stripes run up and down your arms and legs and hug your torso. They wrap around the back of your head like a hood and across your face. You just can’t see them. -DadsRGR8

The pain you feel from a sunburn is your skin cells effectively killing themselves before they mutate into cancer. -BrokenTailpipe

When you get laser tattoo removal the ink doesn’t disappear, you pee it out. Your body’s immune system breaks down the pigments of ink and it flows in your blood stream, gets processed through your kidneys, then you pee out the ink. -Fine_wonderland

There is an urban myth that your fingernails continue to grow after death, which is supposed to explain why dead bodies often appear to have long nails.

The truth is that the soft tissues in the fingers and hands tend to contract as they lose moisture, leading to the appearance of growing nails. -Draculamb

Bodies will move as they’re coming out of rigor. I’ve been bumped by a few (I’m a coroner). Bodies can also make sounds as the remaining air/ gas leaves… 2am in the morgue and I thought I was in COD zombies. -Jar-JarShotFirst69

You have enough fat to make seven bars of soap. -eristhegoal

Food that was consumed can sometimes take up to 5 days to fully pass through your intestines into your colon. So when people say that you are full of s**t, they ain't lying. -sk8r772001

We don't just have one sphincter. When you go NO 2 comes along it passes another inner sphincter which isn't under voluntary control. Meaning you can do oOoOoO with your outer sphincter, but not the inner one.

(You tried, that's okay) Sensory cells can detect whether you're about to pass gas or solid. From toddler age on, you can decide to go or not to go. If the time isn't right (e.g. at a friend's house or no toilet nearby), the inner sphincter can push it back in and store it there for later. -bmb00zld

The front of your tongue is curious, constantly patrolling, and autonomous. It chases the dentist around your mouth and you aren’t even aware of it. So embarrassing and weird/creepy. -AdeleBerncastel