As of 2022, tens of billions of chickens are killed every year to feed humanity’s growing appetite for bird meat. With the rise of avian flu, the number of chickens dying of illness — and being killed en masse preventatively — is even higher.

Highly pathogenic avian influenza can be transmitted among farms by wind, according to a recent study that found air-intake systems spread H5N1 in the Czech Republic.

The outbreak has sickened and killed millions of animals, caused alarm among farmers, and, perhaps most notably to the public, raised the price of eggs.