A cocoon is a protective shelter around an insect. It is made from fibrous material such as silk. The cocoon resembles a casing used during the developmental stage of insect growth. There are several types of insects that make cocoons. Some of these include, bees, butterflies, silkworms and earthworms. Another type of animal that uses a cocoon is the desert frog.
Bees are considered to have cocoons because the queen bee lays eggs in each cell of a honeycomb. When the eggs begin to hatch, worker bees add jelly to the heads of young bees. The newly hatched bees wrap themselves in the jelly creating a cocoon. Bees that are chosen to become queens are fed jelly for longer periods of time to cause them to grow bigger and stronger. After eating their way through the jelly, young bees begin to spin another cocoon until they are fully developed queens, drones and workers.
A butterfly's cocoon is called a chrysalis. Butterflies wrap themselves into the cocoon when they are ready to start their metamorphosis. During metamorphosis, the butterfly does not eat or drink. They are in a state of hibernation that can last from a few days to many months. Most butterflies enter their cocoon during the winter and emerge in the springtime. Different species of butterflies create different types of cocoons. Some create silk pads with abdominal hooks. Other species have silk that supports their midsection like a girdle. The cocoon become transparent one day before a butterfly emerges.
Silk Worm Cocoons
Silk worms are a type of caterpillar that spins cocoons around themselves after one month of development. When a silk worm spins its cocoon, it will stop eating and become yellow in colour. The silk worm will spend three days spinning the cocoon made from hardened saliva. A small spinner is located on the worm's lip that secretes the silk used for the cocoon. The silk worm spins the cocoon in a figure-eight pattern and will remain in the cocoon for three weeks. .
An earthworm will produce a cocoon for young embryos to develop. Earthworms produce cocoons in which their young ones or embryos develop. During mating, worms will attach to each other producing a slimy mucous. This mucus creates a seal that becomes a cocoon. The earthworm will deposit the cocoon deep within soil, keeping it safe from harm.
Desert frogs burrow into the ground for protection against extreme heat and dryness. During the summer, burrowing frogs build cocoons to sleep in. This kind of cocoon is made from a protective layer of dead skin. The dead skin sheds from the frogs body and creates a thin sheet. Several sheets continue to shed to make the cocoon. Frog cocoons cover the entire body except for the nostrils to enable the frog to breathe.