This little blue tit looks tired out and it's because he/she is feeding their little ones and it's a very busy time. I am so lucky in that I have 2 robins nests - one on the back garage and one in the ivy on the side of our house as well as a great tit who has a nest under the eaves. This little blue tit has a nest in a box outside the kitchen window but not one that I can see from inside.