More than 125,000 unaccompanied children have crossed the southern border of the U.S. since President Joe Biden took office. That’s more in nine months than in any previously recorded year.

The record-breaking number includes 112,433 unaccompanied minors who arrived in the U.S. from February to August, the Washington Examiner reported.

The previous record number of unaccompanied children entering the U.S. was approximately 80,000 in the entire calendar year of 2019.

“The reason that the smugglers are sort of abandoning these children is because they know that [the Department of Homeland Security] is going to find [the parent],” said Andrew Arthur, law and policy fellow at the Center for Immigration Policy.

“We have helped them perfect their business model. If they simply drop them over the wall then they’re not going to get arrested by DHS because they can just flee back to Mexico while DHS is too busy taking care of the kid,” he added.

Thousands of children remain in government custody.

The most recent report from the Department of Health and Human Services showed that 10,972 unaccompanied minors were in U.S. custody as of Tuesday, down from a high of 22,264 in May.

Reports emerged on Monday that planes carrying migrant children have been flown by night from areas near the border to New York.

The New York Post said its reporters saw two flights largely composed of children and teenagers landing at the Westchester County Airport.

After landing, some were taken to New Jersey and others to Long Island. Others were sent to locations in New York City or Connecticut.

The Post estimated that more than 2,000 illegal immigrants have landed in Westchester County since Aug. 8.

Similar circumstances were reported at the Jacksonville International Airport in Florida.

In May, WRCB-TV reported numerous nighttime flights of unaccompanied minor immigrants arriving in Chattanooga, Tennessee.

Chartered buses reportedly transported the illegal immigrants to Alabama, Georgia and Florida.

In August, residents of Abilene, Texas, reported that Biden administration officials were using the local airport to fly illegal immigrants to locations across the U.S.

In response, Republican Texas Rep. Jodey Arrington fired off an angry letter to Homeland Security Secretary Alejandro Mayorkas.

“Under your leadership and as a result of the Biden Administration’s policies, the United States has ceded control of our southern border to narco-terrorist cartels which, in turn, has created an unprecedented humanitarian and security crisis,” he wrote.