Capsaicin is the chemical in peppers that gives it the spice that we so know and love. However, this chemical is poisonous to insects and will kill them if they ingest the appropriate amount. This is what prevents the hot pepper from attack and destruction from insects. However, because the pepper relies on animals to spread its seed and mutiply, it is tasteless to most animals and they will regularly ignore spice. The amount of capsaicin present in peppers that grow in warmer climates is greater because of the tolerance of the insects in that area.