The only thing I can think of that may cause more CO2 than I usually have produced in any of my vivs may be the rotting fruit the experimenter had placed in-viv. Yet another reason not to have "feeding stations" in-viv.
Aggression and CO2 machines, it would seem.
Glad you brought that up Rich...there are also a number of people that actually place active FF cultures inside their sealed up vivs. That, coupled with little to no ventilation and high heat must just be a disastrous 1-2 punch.
I put cultures in my vivs all the time too.
All these things are adding to up the fact the CO2 deaths have to be small, because most all of my vivs , at least at some points through the year/s have been or are potential CO2 machines.
I really don't ever have high heat though. That would obviously cause all sorts of issues.
High heat and sealed vivs...hearing about more of this, especially during summertime.