Pennyroyal, the smallest member of the Mint family, has been highly regarded as a repellent for fleas and mosquitos. We like to plant it in hanging basket for the patio. It was thought to purify air and water and was hung in the rooms of sick people because of its strong aroma. Pennyroyal should not be ingested, as Pennyroyal Tea affects the uterine muscles which contract to possibly cause an abortion. Because of this outcome, pregnant women and people who suffer from kidney or liver problems should not handle or use Pennyroyal.