1Can you see the rusty patches on this fallen redwood tree?
2It almost looks like some sort of disease, doesn't it?
3Except it's moving.
4They're ladybugs.
5Thousands and thousands of ladybugs.
6For ladybugs all over the country, this yearly gathering is a once in a lifetime event.
7The culmination of ladybug existence.
8It starts as the cold weather sets in wherever they live...
9Until now, these California ladybugs have been feasting on aphids.
10But when the weather turns, this feast of aphids will disappear.
11That's a signal for the ladybugs.
12Time to go.
13They lift up, like little helicopters - over the garden, over the city.
14Up high, the wind takes over, blowing them toward the nearest mountains.
15Year after year, ladybugs converge in the same spots.
16Which is amazing, because these particular ladybugs have never been here before.
17Scientists think previous generations left pheromone tracks - chemicals secreted through their feet - like a trail of breadcrumbs for them to follow.
18By late fall, it's on.
19Their rusty color is a warning to predators: we taste terrible.
20For the first time in their normally solitary lives,
21they find themselves in a ladybug bacchanalia.
22They're all over each other.
23As winter creeps closer, they'll hunker down together in tree trunks, and underground to hibernate.
24When spring comes, they'll emerge, and take care of any unfinished business.
25This is their last chance to mate.
26They only live a year.
27And then, they'll go home. Never to return.
28Next year, another generation of ladybugs will follow in their footsteps.