An ant is so light that if you throw one out of your window, and because of its size and weight, the air resistance acting against the ant is quite powerful that gravity will not physically pull it down to earth with much speed involved. Ants are blessed with a sturdy exoskeleton, which allows for a softer impact.
They do not suffer any injury from falling from great heights. The impact is the same as if it had dropped only a few centimeters. They have a very tiny mass, and the ratio between their area and volume is too small. When the ant falls, the resistance helps to balance the weight.
An ant won't die after falling from a height. In fact, if you throw an ant from the top of a skyscraper, it will land safely on the ground without sustaining any damage. If you have ever been taught anything on terminal velocity, you are going to understand this better. Terminal velocity simply refers to a constant speed that must be reached by a falling object before it can no longer accelerate, due to the resistance from the medium that is aiding its falling.
When an ant falls at any height, it will quickly reach its terminal velocity and continue to travel with the terminal velocity of 3.9mph. From this point, a falling ant will suffer a great resistance from the medium that is aiding its falling. And as a result, there will be a huge reduction in its speed. Another reason is that ants are very light, so their speed can easily be controlled by air.