Do mud wasps nests have an R value?
the house is almost 100 years old. In another hundred it will be well insulated.
Mudwaspinsulation.JPG (57.1 KB)
roughly R5 per foot
Paul, you are being generous to the insulation factor of the equivalancy of a 1" syrofoam.
Marcel 
Well, that would work to 1/12 the insulation value of styrofoam for the same thickness. To get a R30 you would need to have the wasps nests 6 feet deep. The weight would likely become an issue before you could get enough insulative value.
I would guess that whatever R- factor they are worth, it will be better than what was there before, right. ??
Marcel
And its Eco freindly too 
Do you think they would damage the wiring?
I have seen something similar in a 30+ year old split level. Only about 2/3 of the nests, but it was early fall and I was looking for movement for quite a while before I got in too far.
I think I remember reading they will not return to an old nest.
and cheap.
unless, of course, your allergic to stings.
hospital bills might make it expensive.
Mud daubers may become a nuisance when they construct nests of mud, especially on porches, decks, sheds, eaves, attics, ceilings, walls and under roof overhangs around homes and other structures where people live, work and play. They are considered nuisance pests since nests are not defended and stings are rare. In spite of their formidable appearance,** these solitary wasps are not aggressive **and controls are rarely needed."
I don’t think I’d worry too much about hospital bills. I’ve spent some serious time around these wasps and I’ve never been stung.
Holy Mud Dauber…got wasps?