Which Acid is Present in an Ant Sting?

• Common Name: Formic Acid
• IUPAC Name: Methanoic Acid
• Chemical Formula: HCOOH (or CH₂O₂)

The word 'Formic' comes from the Latin word 'Formica', which translates to 'ant'. Early chemists first isolated this acid in the late 17th century by distilling large numbers of dead ants!

The stinging apparatus of an ant is located at the back of its abdomen. When it stings, it pierces the skin and pumps the formic acid venom into the wound.

The human body reacts to this foreign acid by releasing histamines, which cause the surrounding blood vessels to expand. This inflammatory response is what causes the skin to turn red, swell up into a bump, and itch intensely.

Because the venom is an acid, you can apply a mild base (alkali) to the skin to neutralize it through a chemical neutralisation reaction.

Best home remedies:

1. Baking Soda Paste: Sodium bicarbonate is a mild base. Mixing a little baking soda with water and rubbing it on the sting will quickly neutralize the methanoic acid.
2. Calamine Lotion: Contains zinc carbonate, which is basic and soothes the skin.
3. Soap: Most bath soaps are mildly alkaline and washing the area quickly can help.

Note: Do not scratch the bite, as it spreads the acid under the skin and can lead to a bacterial infection.

Formic acid is not unique to ants. It is also found in the stings and defense mechanisms of:

• Bees (Bee stings contain a mix of formic acid and other proteins)
• Wasps (Note: some wasp stings are alkaline, not acidic!)
• Nettle leaves (Bichhoo Buti) — The stinging hairs of the nettle plant inject methanoic acid into the skin if brushed against.