What prompts some creatures to regularly lose their old outer layers and replace them with fresh new skin?
Many creatures throughout the animal kingdom undergo a process of physical transformation called moulting.
Whether they create ghostly serpent sleeves as a result or just ditch clumps of old skin and fur, shedding is an important stage in an animal’s growth and survival.
The terms moulting and shedding are often used interchangeably, but there’s a slight difference between each process. Moulting is the removal of an animal’s entire skin, feathers, shell or exoskeleton as it grows, which often occurs on a seasonal basis. For example, elephant seals (Mirounga leonina) undergo what is known as a ‘catastrophic moult’ during late summer. As dramatic as it sounds, the ‘catastrophic’ nature of these moults merely relates to the large patches of skin that shed at one time.
During this time, blood flow within the seals is redirected towards their skin to produce a new outermost skin layer, known as the epidermis. This puts their vital organs at risk in the freezing oceans they inhabit, so moulting has to be carried out on land.
Shedding hair and skin, on the other hand, can occur more regularly and be the result of dryness or a temperature change. Snakes generally moult three to six times a year, whereas many dog breeds shed their fur all year round. Even humans unknowingly spend their time shedding old skin and hair – around 500 million skin cells and around 100 hairs each day.
Snakes are some of nature’s best moulters. In the same way that humans outgrow clothes through their early years of life, snakes pe
