Despite their tiny brains, flies have remarkable skills, including being able to avoid bullets. While the flies have a small range of motion, they can circle around another fly in mid-flight and catch it in a split second. This is because they have larger mitochondria than other flies, which powers their supercharged vision. Also, the killer fly has a slower rate of time than a human, making it easier to catch its prey.
Gun barrels are made with spiral grooves that cause bullets to spin when they emerge. A spinning bullet behaves much like a gyroscope – it will resist a force and then tilt back when it is released. Because of the forces that are at play in bullet flight, it is difficult for an object to deflect from its path.
However, bullets can still ricochet after they hit something. The angles of incidence are important. If the angle is acute, the bullet will ricochet. In order for the ricochet to occur, the surface must not be hard enough to absorb all of the bullet’s energy. However, if the surface is soft and can absorb some of the energy, the bullet will simply bounce back.