Is this an insect nest?

[aarona]

Found this on the outside of my home. First picture is before I picked at it. The last two pictures are after I poked it with a stick and pieces crumbled off.  What do you think it might be? I am not sure if it was created by an insect(s)... or simply naturally accumulated stuff. Nowhere else do I see this around my house.

I live in Southern California:





www.screencast.com/t/SQ6Zxmapu55

[livingplanet3]

Looks as if it might possibly be some weathered spray foam insulation (such as this). I've used it to seal up gaps in various spots around the outside of my house, and over time, it weathers and becomes very crumbly from exposure to sunlight.