Parasitic flesh-eating flies are 25 miles from the U.S.-Mexico border, U.S. Agriculture Secretary Brooke Rollins said on Tuesday. 

This is the closest the flies, known as the New World screwworm, have come to the U.S. since state and federal authorities began monitoring cases in November 2024. The flies infest warm-blooded animals and can cause substantial losses to livestock, wildlife and pets. 

Texans are calling on the federal government to do more to stop the flies' northern migration, The Texas Tribune reported. 

In January, Texas Gov. Greg Abbott declared a statewide disaster to prevent the spread of the fly, even though it's not present in the state currently. Jim Hogg County declared an emergency on Monday. 

“There is no doubt that this is a very, very serious threat to our livestock,” Rollins said.