The zombie genre has been going strong since the 1930s, and while there’s the occasional deviation in how they’re portrayed on screen, audiences are most familiar with the these famed dead creatures as brainless and slow but deadly in hordes. The zombies in AMC’s The Walking Dead bear all the signs of the typical zombie: mindless killing machines with the singular goal of devouring the flesh of anyone who crosses their path. The zombies in the Walking Dead may be relatively weak, but over the course of 10 seasons, the show has introduced some interesting concepts to their physiology.

Everyone Is Infected

While the origins of the zombie outbreak in The Walking Dead is unknown, every character in the show is infected with the pathogen that causes the dead to come to life. The pathogen doesn’t kill its hosts — rather it remains dormant, and outwardly the host appears normal and healthy. The pathogen only becomes active when the host dies, reviving some parts the brain and cerebellum in the process which causes them to transform into a zombie. As long as the host remains alive and avoids bites or scratches from the dead, the pathogen will remain dormant until the moment of their demise.

Zombies Have Really Strong Noses

The zombies from The Walking Dead have such a powerful sense of smell that they can detect scents from miles away and can differentiate them between the living or dead. In both the television series and the comics the show is adapted from, human characters can disguise their scents by covering themselves in gore, undead flesh or anything that smells of decay. Over time, the zombies’ eyesight deteriorates, but their heightened sense of smell is their greatest asset and proves the most dangerous to Rick and his group of survivors.

Zombies Have Super Strength

The undead are inhumanly strong and possess enough strength to tear apart a human or animal with relative ease and rip apart limbs with little effort. While the zombie’s strength depends on how long they’ve been reanimated, they can produce enough force to overpower even the strongest of humans, making them incredibly dangerous in combat. However, as the zombies decay, their strength wanes, so you’d have a better chance of survival if you encounter an older zombie.

Zombies Don’t Feel Pain

Being dead with limited brain activity and supposedly no pain receptors, zombies from The Walking Dead feel no pain — or at least they don’t react to pain. They can absorb all manner of physical damage even though their bodies are no less durable — and in fact, sometimes even weaker — than that of a living human. Zombies can survive the worst of injuries, from losing limbs to impalement. Shots to the head, decapitation and spinal cord severing are the only things that can kill or weaken a zombie. As long as their brain is intact, zombies can function normally, even if they’ve lost their heads.

Zombies Have a Very Limited Form of Intellect

Zombies are vastly unintelligent and contain practically no memories or personalities from their past lives. They have no sense of identity and nothing motivates them except to consume the flesh of the living. They are driven purely by instinct; however, throughout The Walking Dead, they can perform very basic tasks like smashing a window with a rock or opening a door by turning a door knob. In the first season, a zombie girl does stop to pick up a teddy bear, hinting at some form of memory to her life among the living. Despite this, the memories don’t last, and in their zombie form they are much less likely to perform any actions that signal any form of intelligence.