Just one fly can lay up to 300 eggs at a time and is drawn "to the odor of a wound or natural opening on a live, warm-blooded animal."

The CDC said screwworms are most common in the tropics and subtropics, but recent cases have appeared in Central America for the first time in years. Mexican authorities told the United States Department of Agriculture in November of a positive detection of New World Screwworm in a cow, according to the Texas Animal Health Commission.

The flesh-eating fly larvae, which were recently detected in Mexico, were declared eradicated from Texas in the 1960s.

"Those enjoying Texas' natural resources have an opportunity to serve as the first line of defense in protecting wildlife, livestock, and human health," said Dr. J Hunter Reed, TPWD wildlife veterinarian, in a news release. "Their eyes and ears will be critical to quickly responding and managing this threat."

Despite there currently being no confirmed identifications of NWS in Texas, it was recently detected in a cow at a checkpoint in southern Mexico, near Guatemala, according to TPWD. The sighting in Mexico follows the pest’s recent northward expansion through Panama, Costa Rica, Nicaragua, Honduras and Guatemala.

The Texas Parks and Wildlife Department sent out an advisory warning hunters, livestock owners, and outdoorsy folks near the southern border to watch out for a flesh-eating parasite known as the New World Screwworm.

The screwworm can be devastating to crops and livestock, as it can cause serious, often fatal damage to living things.