Solution :Stung by hairsof nettle leaves causes burning pain. This is due tothe injection of methanoic acid. Methanoic acid is the SIMPLEST carboxylicacid. It isalso knownas FORMIC acid. It's molecular FORMULA is HCOOH or `CH_2O_2`. It occurs naturally in a variety ofsources, such as STINGING ants, nettles, pine needles, and sweat.