They are probably springtails! As for the arthropod species, I did a bit of research, so here's some of my guesses:
A. Platyarthrus hoffmannseggii
B. Porcellio laevis
C. Trichorhina tomentosa
So those are my guesses! I'm no professional in this area but that's what I think based on my research. Springtails, though, are really great for a lot of things. They break down compost, are hunted by ants, breed super fast, and eleminate dangerous molds. Great to have in any ant/woodlouse set-up!
Currently raising:
Myrmica rubra (1 queen + ~5 workers)
Lasius niger (single queen + ~90+ workers)
Lasius neoniger (3 single queen + brood)
Formica spp. (Queen [likely parasitic, needs brood])
Formica pacifica (Queen)
Also keeping a friend's tetramorium immigrans for the foreseeable future. Thanks CoffeBlock!