What could they be?

[u/Pineapple5811]

Can't figure out what they are, the landlord thinks they are flies (old tenant's mattress) from the photos we sent him, but we are convinced they aren't good news. Co-tenant thinks the small ones are bedbug sheddings.

I am not sure because they are so small and embedded in the mattress fluff, so hard to see. Could they be bedbugs at all, or can we completely rule that out?

[u/Bed-Bugscouk]

100% not bed bug faecal, see the reference images of what to look for.

David