Quote Originally Posted by Spaniard View Post
CO2 poisoining is exactly like falling asleep. Which is why you need an alarm in your home to detect it. It has no smell and brings about drowzyness and ultimately the eternal sleep.

It has been decided that is humane because its effects are proven in animals as well as humans. Anyone that wants to whack a rodent against a hard surface can by all means make that choice, but the fact that people don't see an issue with it is baffling.
Not to be a D or anything but I think what your referring to is carbon monoxide poisoning. Both CO2 and CO are colorless, tasteless, and odorless but CO (carbon monoxide) is a lot more toxic and therefore highly deadly. The chances of dying from CO2 in your home is highly unlikely because it would take a lot to deprive your brain of oxygen, and concentrations of that amount would only exist if you had say... a 30lb block of dry ice in your bedroom.