Also humans, including myself: willingly eats food containing high amounts of capsaicin, something chillies evolved to produce to prevent animals from eating them
The human regularly exposes itself to solar radiation and consumes flavoured liquid toxin for recreational purposes, and yet it does not die, instead it develops a tolerance to these hazards. Science team is reminded to take extreme caution when studying this lifeform.
Not all animals. Mammals (spicy, ow) and insects (insecticide). Birds are unaffected and are the pepper's preferred "conveyance method" for their seeds. It's neat!
Spice preserves, kills dangerous organisms in food. That's why, the higher the average temperature, the spicier the food. Well, except maybe europe, it's more olive oil and vinegar in the southern parts here.