Vaejovidae, Paruroctonus boreus
Also known as the Northern Scorpion, this arachnid doesn't like the cold so we wouldn't see them as far north as Ottawa. In Canada they can be found in southern Alberta and the Okanagan Valley.
You can read more here: http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Paruroctonus%20boreus
Have a look at this video to see them in action: