Suicidal bugs - Or, how can bugs be so resilient one moment, and so squishy the other
 

So, I went to wash my hands in my bathroom and noticed a bitty spider trying unsuccessfully to get out of the slippery-sided sink.

Normally, I'd squish it and wash my hands afterwards, but this time I decided to help it out and set it free on the counter.

After chasing it around a while with my fat fingers, trying not to squish it, I managed to get it to climb on the handle of my toothbrush.
I then put it on the counter figuring it would go hide behind the items there, but no, this little sucker made a mad dash for the edge of the world and just jumped. Didn't even shoot a web out to slow it's descent.

Of course, it survived unharmed and went on it's merry way.

My question is...Why can a bug survive a fall like that (that would surely kill us at an equal height) but are able to be squashed with the least amount of pressure from my finger?

The weight of an object is equally proportional to the force it exerts when faced with gravity. Little weight, little impact.

Also, what you may think is effortless pressure from you index finger is actually a lot of force and weight in comparison to the bug. Consider this, have you ever rear ended another car at 0 miles/h? The force is jarring isn't it? That's because you never anticipated that such slow movement would generate that much force.

Also, 'bugs' have a huge surface area to mass ratio, meaning wind resistance has a much greater effect, lowering their terminal velocity to a very slow speed(relative to say a big mammal like us).

Larger objects aren't able to withstand the same proportional forces as small ones. If a spider were blown up to your size, it would be injured by roughly the same forces as you would.

Ahh, ok, I feel enlightened now.
Thanks, guys. :)