Cayenne pepper, along with bell peppers and jalapeno, are all members of the same species, Capsicum annuum. Cayenne pepper typically provides the heat in mixed chili pepper. In nature the hot taste prevents herbivory from mammals. African farmers are encouraged to plant chilis around their farm to prevent elephant damage, as elephant trunks are extremely sensitive. We measure how hot chilis are using Scoville Units. Cayenne peppers are moderately hot at around 40,000 Scoville Units, compared with 5,000 Scoville Units for jalapenos, and over 1,000,000 for the hottest chilis, which are other species of capsicum. Although we associate chilis with Indian and Thai food, chilis have spread around the world within the past 500 years.