http://www.newsweek.com/bug-spray-infertility-birth-defects-deet-1857749 > Common bug sprays may affect the formation of egg cells during pregnancy, scientists have warned. > DEET, chemically named N,N-diethyl-meta-toluamide, is an active ingredient in many insect repellents. The compound works by interfering with insects' ability to smell humans, essentially making us invisible to them.