Swarms of Ladybugs in Ultra HD

Ladybugs are the only insects I actively try to touch and hang out with. They show up in the garden in the spring, eating aphids and generally going about their business. If I'm lucky, one lands on my hand and I get to count its spots. But what's the life of a ladybug like? How long do they live? Why are they red? Do they ever hang out in big groups?
In the video below, KQED's Deep Look gives us solid answers to all of my questions, tracking ladybug migration and hibernation in San Francisco. I won't ruin the surprises of the video below, but I will say: If you are interested in seeing countless ladybugs all in one place, you're gonna want to see this. (Also, because it's filmed in 4K Ultra HD, you'll probably want to go fullscreen and bump up the resolution to the max!)
For more on ladybugs, check out Deep Look's blog post, featuring animated GIFs of fun ladybug moments.
Fun fact: One time I ordered a large quantity of ladybugs from an online retailer. They're sold to gardeners who are looking to control aphids and other pests. The weird thing is, you can buy tens of thousands of them and they'll show up at your door a day or two later, with detailed instructions of how to release them and encourage them to stick around. (In my case, I think 99% of them left my garden within a day, but it was still quite a sight. Pro tip: You don't need tens of thousands of ladybugs for a small home garden.)