It could be the vast rivers of wildebeests that annually migrate in Africa, or millions of passenger pigeons that once darkened the skies of North America, or the monarch butterflies that travel in gigantic swarms from the US to southern Mexico in the fall, but in all cases, the earth moves and we’re amazed.

This week we want to search out two particular kinds of swarming animals to get a sense for how many of them move en mass together, and how they’re doing these days.

When I was walking through Yosemite Valley in the fall, I spotted a huge number of ladybugs clustered together on a rock wall. I estimated there were at least 1 million bugs packed cheek-by-jowl (or antenna to elytra, in the case of the bugs) along that 50 meters of wall.

1. What’s the largest ladybug grouping together that you can find? (Or a swarm, or a lovlieness of ladybugs, although that mass noun is disputed…. but it’s such a great term!)

2. While you’re thinking about ladybugs in large groups, sometimes vast numbers of ladybugs somehow die-off together. Can you find out how / when / why this happens? What are these mass die-offs called? (In the special case of ladybugs, there’s one particular term that’s used.)

3. The spiny dogfish (Squalus acanthias) is a remarkable fish. Like many fish, they often school in large numbers. What’s the largest report of a dogfish school you can find?

As always, I’m interested in the answers… but also REALLY interested in how you found this out.

What search terms did you use to find the largest ladybug loveliness? What resources did you check to find out about the spiny dogfish schools?

Teachers: These Challenges are especially great for your students. The search process here can be simple, or very, very sophisticated, and it lets interested students dig deep into the natural history of these social animals.