This is definitely an actual phenomenon on HN -- someone posts something interesting and it gets a bunch of HNers to go down the rabbit hole together.
A couple weeks ago there was one about leeches:
"You shouldn't salt a leech that's sucking your blood" https://news.ycombinator.com/item?id=45001005
"How Leeches Made Their Comeback" https://news.ycombinator.com/item?id=45045235
"Leeches and the Legitimacy of Folk-Medicine" https://news.ycombinator.com/item?id=45009629
"This is my brain on leeches" https://news.ycombinator.com/item?id=45037109