If you drop an ant off of a skyscraper would the fall kill it? ?

It has to do with surface-to-volume ratio.  The mass of an ant is around one-millionth of the mass of a person.  Researchers at U of Illinois report that the terminal velocity of an ant in air is 6.4 km/h (because the surface-to-volume ratio is large), while a person could fall at 200 km/h.

Okay, so here's the conclusion I've reached: no, the ants won't die. And they won't explode when they get to the top, either. "A rat is killed, a man is broken, a horse splashes." Many readers pointed out that ants were too small and weighed way too little for them to suffer any damage when it hit the ground.

Its all to do with kinetic energy and terminal velocity. An ant doesnt have to travel very fast at all before the air resistance slowing it down equals the gravitational force accelerating it, which means it cant travel any faster while falling. A quick back of the envelope calculation suggests they wont go above 20mph. But the really important thing is, they've got a VERY low kinetic energy value compared to a human. An ant weighs about 10mg, so the amount of energy they would exert even at maximum velocity would be extremely low. Ants can famously lift many times their own body weight, so they're more than capable of surviving the stresses placed on their body from falling. 

If there is one thing to learn in all subjects it is; Big things are not like small things only bigger.

Different effects dominate at different absolute sizes, the absolute mass, absolute material strength, absolute viscosity of air, etc. affect how things behave at different sizes. So an ant weighs almost nothing and reaches a slow terminal velocity in a few seconds due to air resistance and hits the ground at a tiny velocity with almost no momentum. By contrast, a horse weighs a ton and eventually reaches a terminal velocity of mb 80mph. When that amount of vertical momentum hits an immovable surface you get a sideways explosion.

But the thing about size applies to all subjects, eg a person can't borrow their way out of debit but a country can. You can keep 3 chickens in your yard and they stay healthy, you put 10,000 in a barn and they need to be pumped full of antibiotics or disease will run rife. And so on.

Winds at the height of tall buildings are quite forceful.  Tiny creatures like insects and very small birds would have trouble up there.  An ant falling from a great height reaches a terminal velocity quickly because of its low mass compared to the air resistance of its body.  Small insects are sometimes carried great distances by storm winds.

The very small mass and low inertia of an ant's body is not enough to damage the legs when it hits the ground. 

The comic strip B.C. addressed this situation.  Peter and B.C. observed an ant fall.  One remarked "Isn't it amazing how it just walks away?"  The ant is thinking "I hope I can make it to the cemetery" as it staggers off.

I would think because it is so light the air friction or even wind will slow it's decent and prevent it from reaching terminal velocity, also I think their strong outer skeleton will brace them for the impact. This is all just a guess though