I did a bit of morb studying.
Morbs eat chlorine and fart contaminate oxygen.
Morbs run through hydrogen and fart contaminate oxygen.
I am pretty sure they do not consume it.
Either they should not fart or they should consume it.
Steps to Reproduce
Build a room. Fill it with hydrogen. Lure a morb in it. Watch and enjoy.
This issue has not been confirmed by a developer yet.