FedEx Shipping?

Hi, just a quick question. I received my first snake thru FedEx and was surprised that the box wasn't marked "live animals". I thought maybe there was a code on the box to tell the handler that there was a live animal inside. My snake arrived in perfect condition, no problems there. Just curious how the driver/handler knows there's an animal inside. I called FedEx to see if maybe there was a code on the box or maybe something in the tracking number and they told me they do not ship live animals. I see that a lot of breeders use FedEx so I assumed that this information was incorrect and the person I spoke with at FedEx didn't know what she was talking about. But I'm still curious, how do they know the box contains a live animal? Thanks for taking the time to read this and I appreciate any enlightenment I can get from you guys.

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