Why don't zombies eat each others brains?

Depends on the type of zombie. Not all types of zombies even eat brains.

Those that do probably prefer or only go for living non-zombie brains. If there have been types of zombies that attacked each other, they wouldn’t tend to last very long, wouldn’t be very able to form hordes, since they’d go after each other, etc.

They may be dead, but they can still be discriminating with their culinary choices.

Given that it’s not a very common practice to preserve zombie brains, I’m guessing they prefer their brains fresh and not rotting.

There are vegetarian zombies.
They eat Brussels Sprouts.

Due to a lack of Chianti?

Dietary restriction in the Zombie Bible.

“Thou shalt not eat brains of any soul, living or dead.”

I don’t think zombies have brains.

They want fresh health foods, not something that has already been gnawed on.

No ketchup.

I don’t think they have any. Have you seem a zombie lately? They stumble around barely able to walk and always missing body parts. ewww

They still need their brains to go find a voting booth so they can vote for trump.

@mazingerz88 Zing! too funny! :D

They haven’t the brains to think that they could.

Because, they’re thick as shit.