Anyone know what these might be?

[LMichaels]

So ahead of an impending rain/storm front I went to put the cover back on the Weber Flame. Just a cover I had laying around. Anyway as I was covering it I discovered what looked like a small "acorn" stuck to it. I flicked it off with my finger only to have it turn to dust as if it was actually dirt or mud. I then say these little critters on my deck. No clue what they are

 

[LeviWooten]

Silk worms maybe

 

[LMichaels]

Silk worms maybe

But what made the little "mud acorn"?

 

[LeviWooten]

But what made the little "mud acorn"?did

Did a little google search and I’m gonna bet it was a potter wasp nest, those little worms being the larvae.

 

[TimA]

I believe those are common inch worms. See them all over the place

 

[LMichaels]

Yep, you guessed it except it does not show that species as common here. But, I will lay odds then it's some kind of wasp nest as even the larvae photo looks the same