Here's a tiny bird I hadn't seen before. He was outside my window, and I was able to photograph him easily. In the first photo, he looks innocent enough:
But according to my bird book, the ruby-crowned kinglet has a red patch "usually not visible, unless he becomes excited, at which he flashes it open and the whole crown seems to be gushing blood." He was excited, because he saw his reflection in the window and was trying to chase the "intruder" away. He's a little fella, only 4.25". I really enjoyed seeing this bird.