From death threats and sexual comments to animal abuse and self-harm, looking after 30 students at once is no walk in the park.
Teachers have taken to Reddit to reveal some of the most shocking moments of their careers - namely the moments where they were convinced a student would one day become a criminal.
Some of these stories seriously read like they're straight out of an intense horror-psych-thriller-combo blockbuster. One teacher claimed a student tried to plant drugs on them. Another wrote of a kid who deliberately physically harmed himself, then said he was going to tell everyone it was the teacher's fault.
But that's just the beginning.
One former teacher wrote: "We had a student give other students advice on how to sexually abuse small children in graphic detail.
"He was soon expelled and reported to authorities. Soon after we learned that he had been arrested for posing to be injured on a road, late at night, and when someone stopped to check on him, he shot and killed him."
Another user, alex_isthenewblack, spoke of a young boy who got a thrill out of making the girls in his class uncomfortable.
"He loved putting them in a position where they wanted to move away from him, but they couldn't (sitting on their desk, backing them into a corner, etc), but the thing is is that he was so f**king charming. He was LOVELY. He would say hello and goodbye to me and just smile. His smile was so unnerving.
"He came very close to putting a pencil in a girl's eye once, and was suspended for three weeks because of it. He said he wanted to see what would happen, and just smiled the entire time he was in the office with the headmaster."
That's some serious Ted Bundy behaviour in the making.
In another post, a teacher told of a "very manipulative" second-grader who was a threat to other children. One day, an external figure was brought in to see what was going on.
The user wrote: "The district psychologist comes in to observe. I tell the class that Mr So-and-so wants to hang out with us for a period to see the cool things we're learning about. The student in question shows model behaviour all class. As soon as Mr So-and-so leaves, said student winks at me and says, 'How'd I do?'"
Cruelty to animals is another common theme in the thread. Countless studies have reported that cruelty to animals in one's childhood is a big indicator of later violence and criminal behaviour.
One teacher said they caught their student trying "trying to stab the classroom pet rabbit multiple times".
Another spoke of a student who apparently "broke into his neighbour's yard, stole his pet ferret, killed it, skinned it and pinned it to the door of the neighbour's house".
But user AXPendergast may have won the award for Creepiest Student Ever. They describe the "sweetest little sixth-grade girl", saying she was your standard popular, extremely polite model student.
"I discovered she had an online account where she had planned out - very carefully, mind you - exactly how she was going to kill me and a colleague at the end of the year - tied up to two chairs, back to back, so that she'd only have to use the one bullet from her dad's gun. I'd die instantly, while my colleague would go second."
It gets worse. The user said she actually faced no serious consequences; she was suspended for five days, moved to a different classroom, and remained at the school for the next two years.
Yeah, it's safe to say we all now have even more respect for teachers.