I'm not vegan, and the posts aren't aimed at me. Just have a look at c/lemmyshitpost
Hey, it's fine by me if you want to become a fruitarian.
Please NSFW tag this.
Some of them eat oysters, or so I'm told. They lack a brain and centralised nervous system.
Huh, neat.
"Know" is a stretch. Plants respond to attack by releasing chemicals (e.g. nettles and grasses), curling or retracting their leaves (e.g. acacia), or by changing their morphology (e.g. holly); but they have no nervous system - let alone a brain - so it's not like you're killing an animal.
However, this guy has actually switched to Linux, and is willing to adapt and learn how to use it.
As many as necessary, really. The only reason they start getting removed is because of the risk of infection and stuff being higher than the risk of complications with the surgery after a certain point.
It's complicated, subjective, and probably varies country-to-country.
It's more that there's a higher risk of complications if they remove the old kidneys. However, they do start taking them out if you've had more than two transplants.