On April 21 2013, a family (4 juveniles 2 adults) of Carolina Wrens (Thryothorus ludovicianus) were hanging around a downed tree. The chicks were learning to forage while being actively fed by their parents. In the middle of all this a chipmunk approached which made both parents rather nervous. Then the chipmunk made a darting attack. The wren parents defended their chicks quite effectively. One parent dove on the chipmunk with a flying kick. It was so powerful that the chipmunk was flung into the air. Surprisingly this defensive aggressive act had an unexpected outcome. The intruder fell towards where the chicks were hanging out under the trunk of the tree. This triggered an alarm call by parents. The family dispersed successfully but the parents stood their ground and continued to shadow the chipmunk keeping it at a safe distance. Chipmunks are opportunistic omnivores. They can take eggs of ground nesting birds and reptiles and also their young when the moment strikes.
You can watch the entire sequence of events in slow motion after 00:53.
Below is a short video of the treefall modeled in 3D to give you an idea of the habitat used by the wrens and the chipmunk.