Can anyone explain bug smashing?

I can drive my car around for a month, often at 80 mph on the freeways and
maybe get two or three bugs on the windshield.

Yet an airplane has every leading edge covered in layer of dried bug in a
matter of days.

Wouldn't you think there wouldn't be any bugs up there at 3,000+ feet. If
they are up there, why are they there? All the food is down here on the
surface.

Could it be that your plane is nearly always going much faster than
your car and the probability of a bug smash is proportional to the
square of velocity?

Cheers