Only between members of the Schengen-treaty, afaik. I don´t know whether that applies for new EU countries as well. But even that is more cooperation than the US and Canada seem to have managed.
Thats what I thought. We dont have border guards between our states either. Canada and the US are not the same as the EU. Were just neighbors

Seeing that you are worried about terrorists walking from the US to Canada and thinking of some threads about your mexican border, I wonder how those terrorists came into the US, which is a prerequisite for them to walk into Canada

Youve seen me constantly complain about the state of our southern borders. But terrorists have been caught here that walked in from Canada who had imigrated there. In fact only 50 miles from my home.