Cicadas!
Brood XIII of the cicadas are just starting to mature. They are an absolutely fascinating insect. Every 17 years they come out en masse for a week or two before laying their eggs and dying. The insects in this brood are apparently approximately 3-4 cm in length and make a cacaphonous sound. They are so loud that the Chicago Symphony Orchestra has rescheduled their outdoor performance so that it will not overlap with the cicadas. But the most remarkable fact of all concerns the duration of their lifecycle. Different species have different lifespans, but 13 and 17 years are common. Why is this? 13 and 17 are prime numbers, so their lifespan will not overlap with the lifecycle of any shorter-lived predator.
Hey! My bio prof was just talking about cicadas in class on Wednesday, and their crazy life cycles. The other reason it works is that they come out in such huge masses that they infiltrate their predators with food, so that the predators can't eat them all, and at least some of them end up reproducing. They actually have no natural defenses.
Kiva's right. Cicadas were featured in a few scenes of the Discovery Channel's special Planet Earth mini-series.