The Nuclear Regulatory Commission mails its samples back to the home office.
However, tarantulas are non-mailable.
I finally got around to running all this past the Better Half this morning as he was getting dressed for work. The best examples that popped into his head of “odd objects sent through the mail” were, first, coconuts. “We get those all the time,” he said. Then, the people who mailed an entire brick building to Alaska, one brick at a time, because the shipping costs were too high. I said, “That’s an Urban Legend, isn’t it?” He said, “No, it’s a true story, it’s in the Postal Record occasionally.” (I looked it up on Google, and I notice that several trivia websites have it as “mailing it across Utah”. Maybe there were two instances.)
Friedo’s link goes to the legendary “mailed a balloon and a 20 dollar bill in a baggie” experiments. Letter carriers are still talking about this.
He said the saddest things they have to deliver is when a plane goes down, and the mailbags are salvaged from the wreckage. The mail from that is usually wet and smoke-stained, and is repackaged in Zip-Loc Baggies for letter carriers.
He said the creepiest thing he’s ever had to deliver was a package of cremated human remains. Oh, they deliver cremation remains all the time, it’s no big deal. But this package was leaking.
I asked him about mailing a full can of Coke. He shrugged and said, “Oh, sure.”