You should not have any problem in that case. If you have your books registered by Canada Customs before going into the US, you will save yourself having to pay PST on them when re-entering Canada. Kind of nit picky I know, but it's happened.
The biggest problem you are likely to incur is Canada Customs officials not knowing what to do about the live snakes. It is not a common thing for them. Ontario Agriculture is not concerned with live reptiles (except turtles), I don't know if the same holds true in Manitoba.
Most important of all, be polite to the uniforms.
:eb: Scotty Allen :eb:
"For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return." -- Leonardo Da Vinci