Mirage is not all bad. On the one hand, if there are no other indicators such as grass, trees, livestock, etc., it will show you what the wind is doing. Unlike wind, mirage can’t move a bullet. But it can move the image of what you’re shooting at, so the effect is the same. If you aim at a target with a rising mirage in front of it, the image you see is above where the target actually is, so you shoot, and your bullet goes high.