I went out to fill the bird feeder this morning and saw a small aggregate of what I thought at first were Harvestmen (those spiders that aren’t really spiders). As I got closer I realized it was actually an aggregate of the nymphs of a Leaf-Footed Bug, Leptoglossus phyllopus. I also found the bug’s eggs on the side of the house… and on some of them, I could see the little “doors” on the front of them left open after the nymphs emerged. They form aggregates to help one another keep warm and regulate their body temperature.
You can see the whole album here: https://www.flickr.com/…/mkhnatura…/albums/72157710241916126 which includes a video of the critters, photos of the eggs, and some of the stuff in the yard. The video isn’t that great because I did it with my cell phone, but you’ll get the gist of it.