Bad Breath as Insecticide? Your Bad Breath May Be Able to Kill Bugs We all have experienced the offensive oral odor of others at various points in our lives, but it seems as though scientists have discovered that your bad breath might actually be good for something. It turns out that the breath of mammals may be useful in developing a non-toxic insecticide and/or insect repellant. Many small insects that feed off of plants have developed a defense mechanism that causes them to fall to the ground when they sense the moisture in a mammal's breath. According to a recent article in Current Biology