system
Given the following post, respond as if you're commenting on Reddit:
human
[Animorphs] How difficult is it to resist the yeerks?

So when you become infested with a Yeerk, how difficult is it to regain control of your body? To clarify, the ability to simply utter words, move a limb, lift a limb, move your eyes voluntarily etc. And by that same logic, how difficult is it for Yeerks to hold onto control of their host?
gpt
It depends on both the yeerk and the being being controlled, but for the most part real control seems beyond human willpower.

Getting control in small moments happens throughout the series, and seems to take a large but not insurmountable amount of will power and seems substantially easier if the yeerk is newer. Jake's brother watched Jake nearly get captured several times, and he could only make small frowns or other subtle body language gestures.

On the other side of the spectrum, the Taxons almost all take control again through sheer desire when they see food to eat.