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Here’s Why You Can Mail Scorpions But Not Spiders

The U.S. Postal Service kindly asks that you not send spiders through the mail.

Credit: roswellsgirl/Flickr

Above: The U.S. Postal Service kindly asks that you not send spiders through the mail.

Photo by USPS

The June 26, 1955 edition of the Postal Bulletin informs postmasters that from here on out, they "shall accept packages containing live scorpions."

After researchers at UC Riverside studying the poisonous brown widow spider put out a public call for samples, the post office had to remind citizen scientists that mailing spiders is against the law.

On Sunday, the U-T San Diego ran a story about this tangled web of misunderstanding:

The scientists were seeking more of the spiders to study ways of controlling them because they have become backyard pests. They have received more than 250 specimens after issuing their appeal in June. Children have been able to participate in the citizen-science movement and families have gotten rid of these unwanted visitors, which are cousins of the black widow spider.

But the U.S. Postal Service was alarmed when it got a flurry of the arachnid packages. It turns out that the UC Riverside researchers weren’t aware of postal code sections declaring that spiders — like flammable, perishable or liquid items — aren’t allowed.

The article notes that despite the prohibition on mailing spiders, it's totally legal to ship another poisonous live animal through the mail under certain circumstances.

Scorpions can be mailed "for the purposes of medical research use or the manufacture of antivenin." As long as you clearly label your package "Live Scorpions," U.S.P.S. will deliver them.

KPBS reached out to the U.S.P.S. Postal History department to find out why scorpions get a stamp of approval but spiders don't. As with most arcane government regulations, the most plausible answer seems to be "lobbyists."

The post office's Stephen Kochersperger traced the origins of this rule back nearly half a century:

The exception for mailing scorpions dates from 1955 when Public Law 108 permitted the mailing of live scorpions, provided they were sent for purposes of medical research or the manufacture of antivenin. Since the spider lobby has not yet moved Congress to amend the law to allow for mailing spiders, they remain nonmailable.

Hear that, arachnologists of America? If you want the the post office to carry your specimens, hire a lobbyist.

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