Do the Dead Breathe?

[Perpdepog]

I was just re-reading through the Playing Undead section of Book of the Dead again, and I just realized ... there isn't any provision made as to whether the undead still have to breathe. They have new hungers, but that specifically covers food and drink. They no longer sleep as such, but that's a different process.

So my question is, do the undead breathe? I want to say no, because duh, but this is rules language, so it's a question worth asking. It's also relevant because PC undead, unlike monster undead, do not have a blanket immunity to inhaled poisons or other airborne attacks.

Also, if undead do have to breathe, does this mean it's possible to suffocate a skeleton, or garrotte a ghost?

[The Raven Black]

Do they breathe ? Likely, otherwise they cannot smell. Which seems to imply they can be poisoned by a gas, barring resistance/immunity to poison.

Do they need to breathe ? Can they suffocate ? Common sense would say no. Not sure abour RAI though.