I had a seed starting tray outside for a few weeks. This morning I picked it up and this nest beginning was underneath. There was also one insect that looked like a bee. It was small, dull colored, had a hairy body, and the legs looked like a bee's rather than a wasp's. This doesn't look like a beehive, though. Any ideas?
I wonder if it is a type of Mason Bee. I was just looking at an ad for a Mason Bee "house", so looked it up in the bug guide. They are harmless, but great pollinators. Your tray looked like an ideal spot for the female bee. :)
http://en.wikipedia.org/wiki/Mason_bee
I believe that Chillybean is on the right track...
