What is molting?
A mature feather is not a living feather. So damage or wear on a feather cannot be repaired. Birds solve this problem by periodically replacing their feathers in a process called molting. Though this may be an ongoing process, it predominantly occurs once or twice a year for most birds usually in the spring or fall. It also occurs symmetrically. The same feathers on the right side will often molt at the same time as the left side. This helps to maintain the ability to fly in a balanced manner. Typically the fifth flight feather (both sides) falls out first and then flight feathers alternating on each side of the fifth flight feather will fall out in turn. This process will continue until all flight feathers have molted. The sequence typically takes weeks or longer to complete. As feathers fall out, new ones called pin feathers take their place. These are living feathers with a blood supply inside them. As the new pin feather matures, a thin sheath of keratin covering protects the pin f
Molting is for growth or regeneration. The Hermit Crab sheds its hard exoskeleton and a new, larger one is revealed. It eats the old exoskeleton for calcium to help harden the new one. This process takes about ten days. Small crabs may not molt for eighteen months or longer. They may bury themselves in the sand or gravel during molting. This is because they are more vulnerable during this time period.
