The basic principle behind getting relief from an insect bite is neutralization. The insect sting/bite may produce a secretion which is acidic or basic in nature. Based on that, one can choose basic or acidic substance so as to neutralize the effect. This way, less pain is experienced. Apply an alkaline substance if the sting is acidic and an acidic substance if the sting is alkaline (basic).

For example, ant stings are acidic (methanoic acid). Hence it should be treated with an alkaline substance like baking soda.