Diethyltoluamide (aka Deet) is an insect repellent used to prevent bites from mosquitoes, biting flies, ticks, and fleas. Bear in mind that this product does not kill mosquitoes- It only deters them. It does so by “interfering with neurons and receptors located on the mosquito's antennae and mouth-parts that detect chemicals such as lactic acid and carbon dioxide”. Before using this topical medication, you should tell your doctor about your allergies, or if you’re using other drugs. Apparently, Diethyltoluamide is safe during pregnancy. However, it is only safe during breastfeeding when used as directed. It is worth noting that the following side effects are considered rare. However, they might occur from time to time, and when they do, contact your doctor immediately. These side effects are as follows: confusion, changes in skin color, skin rash, slow heartbeat, and mood swings, among others.