Feather These barbules have minute hooks called barbicels for cross-attachment. Down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular "calamus" (or quill) which inserts into a follicle in the skin. The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base (proximal umbilicus) and a small opening on the side (distal umbilicus). Hatchling birds of some
A Bird in a Bonnet way into the hat shop. Just as Tweety hides at a table, Sylvester runs in and tries to rummage through the hats to look for him, but the sales lady catches him in the act, and chases him out. Just as the sales lady comes to the table where Tweety is hiding, Tweety stands real still on a hat, making the sales lady think that he's a cute little stuffed bird on a hat. After Granny tries it on, she thinks the same thing and buys the hat. Tweety soon realizes the joys of being said "stuffed bird" has a