According to reports, scientists have recognized the chemicals, which lead to the mosquito-repelling activity of sweetgrass that is a plant conventionally used by some Native Americans to keep away the bugs.

It was found in laboratory tests that two sweetgrass compounds repelled mosquitoes from enticing fake blood samples, in addition to the broadly-used repellent Deet.

According to Charles Cantrell, a research chemist who works for the US Department of Agriculture, "This is the fourth plant that we've investigated in this manner. The neat thing about this one is that it produces a compound, coumarin, which has a great odour and was known... to have some repelling properties. And it's very safe". Dr Cantrell was present in Boston at the 250th national meeting of the American Chemical Society, when he gave the statement.

He told journalists that coumarin has an interesting story. Avon 'Skin So Soft' manufactured a product back in the 90s that people found it working well as a repellent for insects. The product wasn’t promoted as an insect repellent; however, consumers knew about its effectiveness.

Dr Cantrell said that scientists carried out an investigation and among the ingredients in Skin So Soft, one was coumarin.

Dr Cantrell said that in the face of this, at present coumarin is not registered or marketed as a repellent. He and his colleagues identified another main ingredient in sweetgrass as phytol, which is a common ingredient in essential oils from plants. Phytol is also known to repel insects; however, at present it is not marketed for this purpose.