Molting is simply the process of animals replacing their hair or feathers with new ones.  Here is an overview of which animals molt, when, and why they do it.

Sometimes I wish that I could molt, just crawl out of my old skin and get some nice, fresh, clean skin.  Or maybe I could lose all of my hair and then quickly grow new, healthy hair that would look good and that would help me attract a date.  There are lots of different kinds of animals that lose some or all of their hair or feathers at different points in their life.  Different types of animals molt at different times of year or different stages in their life for a variety of reasons.

What is Molting?

To begin with I thought it best to start with the basic meaning of the word.  The dictionary definition of molting is – to shed the feathers, skin or like that will be replaced by new growth.

Or another definition states – the process of shedding an external skeleton for the purpose of growth or change in shape (such as what happens during metamorphosis).

Those are the dictionary definitions, but I’ll put it in my own words just to hopefully, make it simple and understandable.  Molting is a time when an animal gets rid of some hair, feathers, or even an exoskeleton to allow for new growth.

What Animals Molt?

The different kinds of animals that molt include birds, insects, reptiles, and even mammals.

Why Do Animals Molt?

There are a lot of different reasons that animals molt.  Some do it in order to allow them to grow bigger.  Others molt in order to look good so that they can attract a mate.  Some animals molt because they need to get rid of their thick winter coat that allowed them to survive the winter.  Here are some of the main reasons that the different kinds of animals molt:

Birds

Why – Birds molt their old feathers in order to grow new, healthy feathers.  The new feathers will often be a different color than the old ones.

When – Birds will molt most or all of their feathers at different times during their life or during the year.  The new feathers that birds grow will indicate a different age, sex, or time of year.

During the mating season, male birds will grow brightly colored feathers in order to attract a mate.  This is like a person putting on their fanciest clothes in order to get attention.  Male birds will grow brightly colored feathers in order to get the females attention and to show the females how healthy they are.  It’s like showing the females that they have access to good resources and they are strong and would make a good mate.  You can learn more about the common birds of the Rocky Mountains here.

Insects

Why – In sharp contrast to humans, insects have their skeletons on the outside of their body.  This is called an exoskeleton.  The skeleton on the outside of their body does not grow as the insect grows older and bigger.  Due to this, insects molt or crawl out of their old exoskeleton in order to grow a new, larger exoskeleton.  Molting for insects is just part of the process of growing.

When –  Insects will molt when they change from their larval or nymph form into an adult.  This may take place at various times throughout the years, but most commonly happens during the spring and summer.  You can learn more about the common insects of the Rocky Mountains here.

Reptiles

Why and When – Reptiles shed their skin because their skin does not grow larger.  This means that as the snake, lizard, or turtle grows larger the skin simply gets tighter.  At some point the reptile needs to molt or shed its old skin in order to grow new skin that is bigger.  Snakes shed their entire skin all at one time.  On the other hand lizards and turtles shed their skin in smaller pieces.

Mammals

Why and When – Some mammals shed fur throughout the year, but others will shed or molt their fur at certain times of the year.  For example, one of the main times of year that they do this is in the spring.  One of the winter survival strategies for mammals that live in very cold climates is to adapt by growing a thick winter coat.

For example, elk or mountain goats grow thick winter coats.  Then when the weather warms up in the spring they need to get rid of their thick winter fur.  At that point in the year they look ragged and scruffy as they are losing that old winter coat.  You can learn more about the common mammals of the Rocky Mountains here.