Whew! I've been reading, but haven't had time to sit and type until now. Margaret, your moth looks like a Polyphemus Moth. Since you're in Canada, I don't know what you've got in your parts. I wonder if it's the same moth and maybe a different common name? As for the one in the video, it never really opens its wings, but I know the Atlas Moth is that large. Even the little butterflies tickle; a moth that large would let itself be known!
Robin, awesome article and I hope we can do some stuff for National Pollinator Week next year.
And since it came up and since I'm moderator now...
I don't have any problem with folks discussing host plants or butterfly related plant things on the thread. I suppose the idea of this thread might have been originally just to showcase our photos, but I think it has become the place where we also come to learn and share information. So talking about milkweed germination is fine with me. I guess if you wanted to get really technical about it or were maybe looking for particular info on one type of milkweed, you might want to start a new thread. Or maybe post in one of the regional forums to get a sense of how things grow in your area. I live in opposite land (aka Florida), so instructions on seed packets don't often work for me. But otherwise, this is a fine place to come and ask questions like that. And as things slow down in the winter, I expect there to be less photos and more conversation. We can all plan our spring gardens!
Also, since we have some new folks that have dropped by recently, don't be afraid to ask questions! I've been raising butterflies and moths for eight years now but I was once a newbie, too! And I'm still learning all the time. If one of us mentions a term or something you don't know, feel free to ask us to explain. Sometimes I'm not sure how much to explain myself because I know some people have been on here a while and I don't want them feeling like I repeat myself all the time, but at the same time, we have new folks and maybe some lurkers who wouldn't understand me unless I was really detailed. So I might take it for granted that everyone knows something, but if you don't, that's okay! I love feeling smart so feel free to let me share my knowledge! Plus, my family gets bored when I talk too much about caterpillars. Who else can I discuss frass (that's caterpillar poop) with?
No pictures today because I went to the dentist, ran errands, and then took a nap. I stopped by the grocery store and bought organic dill for the Black Swallowtails. The biggest ones started gut purging. I had four do it today.
And I had to move the others to clean the container and they all started stinkhorning me. I said, "Someone remind me that they turn into beautiful butterflies because I can't remember why I'm doing this."
I've always wondered what to look for. Also, it's interesting how some caterpillars eat a lot and some not very much at all. I've noticed the GS's (Giant Swallowtails) don't eat much at all. 
