Double fleshy appendix hanging under the beak and the throat(breast) of most of the races of hens and cocks.

The thousands of soft 'branches' that spring out on either side of the shaft and angle toward the tip of the feather. Each barb has tiny parallel branches called barbules. See image below. The barbs should be trimmed when making a quill pen because they form a natural airfoil (that helped the bird fly) and cause unwanted resistance when writing. They can also get in the way of the writing hand. Primary flight feathers, which are most suitable for making quills, can be identified because they have a much narrower barb on one side of the shaft.

A part of the worker bee's sting which is used as an anchor.

See Flow diverters.