The question is...

...how did he keep them all quiet during the whole flight?

A man who smuggled Asian songbirds into the country by hiding them under his pants during a flight from Vietnam to Los Angeles was sentenced Monday to four months in prison.

Sony Dong, 46, of Garden Grove, was also ordered to pay $4,000 in restitution to federal authorities who are caring for the birds.

[...]

In April 2009, customs officials determined that Dong was scheduled to fly from Vietnam and arrive at LAX. They conducted an inspection and saw bird droppings on his socks and feathers peeking out from under his pants.

Lessons to be gleaned from this incident? Don't try to smuggle rare birds into the country. But if you absolutely have to, wear roomy pants, attach them fairly high up on your leg, and point them butts-and-tail-feathers-side-up.