Thank you all for the great suggestions.
Unfortunately though, it strikes me that most of these are regular documentaries that may not interest our boys quite yet (particularly DS5). They love learning about science, but still prefer it to be "fun". SciQ was perfect (learning about the science of movie special effects, etc.), so I was hoping there'd be something else like it out there.
We've tried Life of Mammals and they got restless pretty quickly. We may have to wait a bit longer for regular documentaries.
