All herps going into or out of the USA are supposed to be inspected by US fish & wildlife.
There is a fee for this inspection it's 55US for non CITES and 75US for CITES.
These inspections are generally done at what are called "designated ports" Unfortuately there aren't any "designated ports" on the border, they exist only at large US airports.
Inspections can be arranged at border crossing points, but this must be done at least 48 hours in advance so that an officer can be dispatched from the closest USF&W office.
As Linds points out, they are sometimes leinient on small quantities of NON CITES pets.
However, you're really supposed to have both a USF&W import/export license($50 per annum) and also a special permit called "Exemption from designated port"....This is because you are facilitating a transaction at a place other than a "Designated Port" This extra permit is only 25 US, but you have to apply in advance for both the license and exempt from des, permit. It takes a few weeks to get.
Quite a few of us Canadians now have all this stuff.
There is quite a bit of variability in how customs & fish & wildlife officers handle people that don't have all this.
Sometimes, if it's only a few, they will inspect only and let people go. Other times, they will inspect, and charge you for the inspection. Other people with any quantity, will probably find even if they don't have the required export license, they might be charged for it on the spot , in addition to the inspection.
Customs and USF&W have a load of power and it's their prerogative on exactly how each non conforming case, is handled.
Many people simply bring animals out of the US and declare them with Canada customs, since normally that is the first officials you see.
Providing they aren't CITES, this doesn't break any Canadian law,and they'll take your tax money and even give you a receipt, however, you've already broken US law at that point by removing them from the US without an inspection and filing of a 3-177 form.(they do that during the inspection)
Canadian customs officers won't tell you about your breach of US law, because it's not their jurisdiction. They may not know anyway.
Problems only arrise, if you are turned back with your animals, or if they call and expert on the US side to confirm your animals aren't CITES.
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