>The weirdness is that dark matter doesn't interact electromagnetically (although neutrinos don't do that either)

How do we know that Dark Matter is not just a lot of free floating neutrinos? This seems like too obvious an answer so I assume we have a reason.

EDIT: Never mind, I found it on Google.
What rules neutrinos out of the running for dark matter is that in the Standard Model, they are considered “hot” particles, meaning they travel at speeds close to the speed of light. For a particle to constitute dark matter, it must be “cold,” or travel slowly compared to light.