Folk wisdom in countries like Mexico, where people love to eat hot and spicy food, is that chilli can ward off illness. There may be some truth to that, at least for chickens. Adding capsaicin, the spicy component of chilli peppers, to chicken feed increased resistance to Salmonella.

Apparently, the spice inflames the intestine, and this inflammation may be what prevents Salmonella binding to the intestinal cells. The chickens don’t seem to mind the heat, as they, along with most birds, don’t appear to taste the pepper. However, rodents do, so adding pepper to bird feed can also keep mice and rats away.