What do barbecued monkey, ostrich eggs, and whale meat sausage have in common? They've all recently been seized by U.S. Customs and Border Protection specialists at O'Hare International Airport, and such seizures are on the rise.

Elvis, a Customs and Border Protection K-9 and his agriculture specialist handler, Officer Martin Schultz, are on the case. The hound dog's nose is so sensitive, he's able to sniff out just the remnants of undeclared food brought into the U.S. – like sandwich residue on a panini press.

Just when you think he's taking a blue suede snooze, bingo, he sniffs out an illegal sausage inside a checked bag, and Elvis has left the baggage claim with some undeclared cured meats.

"Think of the outbreaks that you often hear about in the news. That's because somebody didn't declare something," U.S. Customs and Border Protection Chief Agriculture Specialist Cory Everton said.

What kinds of things have they found? An egg from a Giant African Snail. Glue made from the skin of a donkey. Entire hams and salamis. Moose meat sausage Whale meat sausages. Duck tongues.

Officers recently showed CBS News Chicago a table full of undeclared agriculture seizures seized in a span of only 24 hours.

Monkey, antelope and lizard meat are also regularly on the menu.

Everton explained that customs officers' first concern is about undeclared items that could transmit diseases like foot-and-mouth disease. 

"African swine fever. We worry about Newcastle disease; that's a disease of poultry. Avian Influenza; that's a disease of poultry, but also can jump into humans," he said.

The other concern is insects and other pests that could be in fruits, vegetables, and other produce; some that can ravage American crops, which is why CBP is working harder than ever before and seizing more undeclared agriculture.

In 2024, CBP conducted 201,222 K9 passenger inspections, and had to issue 78,874 notices — up significantly from the two years before.  CBP conducted 179,778 such inspections in 2023, with 70,098 notices; and 136,307 inspections in 2022, with 73,256 notices.

"An increase in international travel post-COVID. A lot more people are traveling. Some of it is our officers are becoming very good at what they do," Everton said. "We don't expect you to know the rules. We do expect you to be truthful."

Which is why, if Elvis in the International Terminal baggage claim, you can't help falling in love with him, especially when he's helping save American farms.

Travelers entering the United States must declare all agricultural products to a CBP officer. If you have any questions, head to dontpackapest.com.