Why the US Drops 14 5 Million Flies Over Panama Every Week

Added: 2026-05-17

[00:00:00]Did you know that the United States drops around 14.5 million flies over Panama every single week?

[00:00:06]It sounds unbelievable, but Panama actually supports the operation.

[00:00:11]In fact, it helps create a protective barrier that defends not only Central America, but also North America from a deadly parasite. The threat comes from parasitic insects called screwworm flies.

[00:00:24]Female screwworms lay hundreds of eggs inside open wounds on animals and sometimes even humans.

[00:00:30]Once the eggs hatch, the larvae begin feeding on living flesh, causing severe infections, intense pain, and often death in livestock.

[00:00:39]To stop the spread, scientists developed a remarkable strategy known as the sterile insect technique.

[00:00:44]Millions of male flies are bred in specialized labs, sterilized using radiation, and then released into the wild.

[00:00:52]When female screwworms mate with these sterile males, their eggs never hatch.

[00:00:57]Over time, the parasite population collapses. [music] This method was so successful that by the 1960s, the United States had completely eliminated screwworms from the country.

[00:01:07]But instead of defending the entire long US-Mexico border, officials realized it would be far cheaper and more effective to stop the flies at the narrowest point connecting North and South America, the Isthmus of Panama.