I wanted to check about getting passports for the kids to go to Canada, so here is the official info: https://travel.state.gov/travel/cis_pa_tw/cis/cis_1082.html#entry_requirements
Entry into Canada is solely determined by Canadian Border Services Agency (CBSA) officials in accordance with Canadian law. Please see the CBSA?s website for details. Canadian law requires that all persons entering Canada carry both proof of citizenship and proof of identity. A valid U.S. passport, passport card or NEXUS card (see below) satisfies these requirements for U.S. citizens. If U.S. citizen travelers to Canada do not have a passport, passport card or approved alternate document such as a NEXUS card, they must show a government-issued photo ID (e.g. Driver?s License) and proof of U.S. citizenship such as a U.S. birth certificate, naturalization certificate, or expired U.S. passport. Children under 16 need only present proof of U.S. citizenship. (Please see below for important information concerning re-entry into the United States).
When returning to the United States from Canada, it is very important to note that all U.S. citizens are required to present a valid U.S. passport to enter or re-enter the United States via air. For entry into the United States via land and sea borders, U.S. citizens must present either a U.S. passport, passport card, NEXUS card, Enhanced Drivers License or other Western Hemisphere Travel Initiative (WHTI)-compliant document. The only exception to this requirement is for U.S. citizens under the age of 16 (or under 19, if traveling with a school, religious, or other youth group) who need only present a birth certificate (original, photocopy or certified copy), Consular Report of Birth Abroad, or naturalization certificate.
So...under 16 only needs a birth certificate if driving to Canada, which is what we're going to do.
Re: FYI: passport info for Canada (since I brought it up)
Can I just give you one little tip call the board you will be crossing at and ask just to make sure.
The reason I say this is I have had to get a one year work visa 3 years in a row and it had to be done at a boarder crossing I ended up doing it at 3 different ones and each time they asked for different doc's. (I had everything it said I needed on the website)
Something happened two different times when I traveled outside of the US with a travel visa (while I was waiting for my green card). The stories are endless for me and boarder crossings.
I find sometimes it all depends on were you cross and who you get. One time they didn't even want to see mine or DD's passport or the letter that DH wrote saying I could take her out of the US. (We were driving into canada).
So I would call the board you will crossing at they will be able to tell you what they look for. I hope you don't need to get them passports.