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."

A parasitic worm eradicated in the United States nearly 60 years ago could be threatening a comeback, Texas wildlife officials warn. The New World Screwworm was recently detected in Mexico, and the Texas Department of Parks and Wildlife is asking people in South Texas to watch out for animals affected by the screwworms.

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

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 Texas Parks and Wildlife said the screwworm was found in a cow at an inspection checkpoint in the southern Mexico State of Chiapas.