The flies are in the mail

In 2002, the Bloomington Drosophila Stock Center at Indiana University – one of the world's best known sources of fruit flies – had a consignment destined for overseas returned by the US Postal Service (USPS). The center's codirector, Kevin Cook, learned that the package had been deemed in contravention of USPS international postal regulations. The Bloomington center mails tens of thousands of fly cultures overseas each year, and "this was only the first time a postal inspector had sent back a package," says Cook.

Cook had looked through the USPS's mailing regulations in the past. The domestic rules expressly permitted posting of Drosophila, but the international mailing regulations were less clear. In the past he had interpreted them as allowing international mailing, but now he was less sure. Cook immediately wrote to USPS asking for official clarification and the answer that came back was not the one he was hoping ...