Frogs can do semi-controlled free-falls from heights. Tree frogs can glide from one to another. Any creature small enough can survive large drops as the impact forces are calculated using F=M X A, and if M is small, then F is small. Also air resistance on small light creatures is relatively high, so they never reach a speed fast enough to kill them.
There's some great footage somewhere of ducklings leaving a nest at the top of a tower-block and plummeting into water, only to chuckle and paddle off like they did it all the time.