What is this mold? White furry looking stuff?!?

[Billbill84]

Hi all. So I've noticed this white furry looking stuff on the rim joist area of basement. Nothing's ever moist or wet down there and RH is never over 40%
There's two spots that look like old cob webs but further back in there I see it on subfloor but on subfloor it's a bunch of tiny furry looking balls about 1/4" or smaller in size (see pics).
Is this white mold or cob webs or what?!? Thx

 

[havasu]

Time to dilute bleach 50/50 with water and spray the area. Then try to remove the humidity from the area.

 

[Billbill84]

Time to dilute bleach 50/50 with water and spray the area. Then try to remove the humidity from the area.

Copy I'll try that. This is a single open area of a fully finished basement so it's the only spot I can see it. Not sure how it got there last owners ran a dehu 24/7 and I do same 24/7 in summer and RH is NEVER above 40%. Actually about 30 in summer and 35% in winter. I'm running two 70pt dehu's down there.

 

[Jeff Handy]

I think it is from spiders catching other insects.

 

[Billbill84]

I think it is from spiders catching other insects.

Yeah that's what I was thinking. Especially because of the same stuff that's just a bunch of small round balls that aren't on the rim but hanging on the bottom of the subfloor. A buddy of mine said it looks like a spider coon or spider eggs.
None of it is flat or spread flat along the surface like mold so that's another reason I'm thinking insects/spiders

 

[Jeff Handy]

As kids, we used to call those spider eggs.
I think some spiders do spin a little ball around their baby spiders.
But they also spin those to wrap up their dinner victims.