Nitro would like a word.

The three-year-old chocolate Lab working with Customs and Border Protection at Philadelphia International Airport recently sniffed out $44,690 in undeclared cash from a passenger headed to Cancun, and federal officials are using the moment to remind summer travelers that bulk cash and airports are a combination that tends to end badly.

The traveler, a 54-year-old naturalized U.S. citizen from Peru, had cash stashed in his pockets, in separate envelopes, and inside his carry-on, according to a CBP press release. When officers asked what he was carrying, he said $10,000. That’s the magic number, the federal threshold above which international travelers are legally required to file a declaration. He had considerably more than that.

A thorough inspection found considerably more than $10,000. Officers seized nearly everything, leaving the man $240 for what officials described as “humanitarian purposes.” The remaining $44,450 went with CBP.

Acting Area Port Director Elliot Ortiz didn’t mince words. “This traveler concealed currency in multiple locations for the purpose of evading federal currency reporting laws, but no amount of concealment can hide bulk currency from Customs and Border Protection officers and especially from CBP canine Nitro.”

Traveling with a lot of cash isn’t a crime. Not reporting it is, and CBP takes it seriously because undeclared bulk cash is one of the oldest methods for moving money tied to drug trafficking, tax evasion, and financial crimes across borders without a paper trail. Cross a U.S. border with more than $10,000, and you’re required to fill out an official declaration form. Skip it, and CBP can take everything on the spot. Getting it back means hiring a lawyer and hoping for the best.

CBP seized an average of roughly $180,000 in undeclared or illicit currency every single day during fiscal year 2025. And Nitro has company. A Belgian Malinois named Pub has been equally busy at Atlanta’s Hartsfield-Jackson International Airport, helping federal agents seize nearly $75,000 in undeclared currency in just the first three months of 2026, including $44,432 headed to Qatar in February and $30,417 bound for El Salvador in March. Pub accounted for roughly 20% of all undeclared cash uncovered at the airport during that period.

The dogs are good at their jobs. The form takes five minutes. Do the math.