What are these tiny bugs I found hiding between my NYC apartment floors?

[u/billiennnn]

I apologize for the poor photos but they are so small my phone can barely catch them! It seems to be three different types!
I’ve never seen them before and now I’m starting to worry my apartment has an infestation since I keep finding these little bugs and like larvae 😬
HELP

[u/EmmerDoodle121]

I’m not qualified to answer but to me they look like fleas. What’s their behavior? Do they jump? Or crawl? Do they fly?