system
Given the following post, respond as if you're commenting on Reddit:
human
[Zombies] How can zombies tear human flesh so easily?

Have you ever tried biting another human with your HEALTHY teeth? It is really hard to make a mark, let alone take a chunk out! How can zombies do it so easily?
gpt
You lack practice or jaw strength, from experience I'd say that it's extremely easy to draw blood by biting, just most people would prefer not to be biting as a day to day interaction and most people that want to be bitten would like you to stop *juuust* before that point.

People lose fingers to bites in fights all the time so small bones aren't an issue to someone that seriously wants to bite you and the strength in the average human jaw and neck are greater than the force needed to tear flesh away from your bones but it'd stress them. Your body is capitulating to the feedback from your muscles. Also humans don't typically use their mouth as a weapon unless something is very wrong survival-wise, you'd only snap at someone to get back into punching or weapon using range.

Zombies have no pain to fight and no cares about tomorrows health and no solid instinct for self preservation.  They have no social qualms about biting and directly wish you harm. Not being tool using level thinkers biting is the go to weapon for them. 

Tearing the living flesh from a human would  be hard work but doable but for a mindless biter that work wouldn't even register.