Rove beetle

7168.        These bugs have been found in my bed and have been cause huge welts on my skin when they bite or sting. Calgary, Alberta. Canada

Number 7168. The image is too blurry for me to be certain, but it has the appearance of a rove beetle (Coleoptera: Staphylinidae). That being the case, it is very unlikely to have caused your symptoms. The only rove beetles known to cause any skin lesions are in the genus Paederus, and these are strikingly coloured, with alternating bands of black and orange – Click here for an example. Also, they need to be crushed against skin in order to cause any harm.