Pepper is nesting.
A mother hummingbird will sit in a nest and use a wing to press the nest against her body to mold it into the perfect shape. She will press her rump into the center of the nest and against the walls to round the inside. She also uses her feet. With one foot hanging onto the nest and the other stomping the nest, she will compact the material to make a solid sturdy nest bottom ~World of Hummingbirds