I spent some time last week watching a pair of chickadees excavate their nest. They are just as entertaining and frenetic in the spring as when at winter feeders . Both worked on excavating the nest and one was so impatient to get in that it looked in to see how the other was doing. They were laying in carpet (grass, etc.) on Saturday so the nest must be complete. Hopefully there will be some young to see in a couple weeks.