Because of the composition of the exoskeleton. It must of necessity be tough to serve its function. Since it is inflexible, the organism has to periodically shed it (moult) in order to grow; a process called ecdysis.
Arthropods molt (moult) in a process called ecdysis. It is necessary for growth because of the inflexibility of the exoskeleton. The old shell remnants are called exuviae. Note that the term 'anthropod' should not be confused with 'arthropod'; anthropods are humans or humanoids and do not moult in the canonic sense.
the outter skin. as the arthropod grows, the outter skin doesn't grow with it. than it gets rid of it by molting!
The main reason is how weak and vulnerable they are just after molting. The new exoskeleton is still soft to allow growth of the animal. The other is the reason they hide DURING molting - it renders them immobile, some species have to lie on their back for hours on end and can't defend themselves.
Most only do so in larval/juvenile stages, when it's time to grow. Some arthropods such as tarantula females continue growing and molting until death. Also, when damage has occurred (torn off leg for example) molting can be induced earlier to develop and grow new appendages. :)
An arthropod
The exoskelton of an arthropod is hard, and thus cannot accomodate growth. So an arthropod must periodically replace it.
Ecdysis is when an arthropod molts its exoskeleton. Molting is necessary. The arthropod exoskeleton is inflexible, so, for it to grow larger, arthropods must molt.
Arthropods molt (moult) in a process called ecdysis. It is necessary for growth because of the inflexibility of the exoskeleton. The old shell remnants are called exuviae. Note that the term 'anthropod' should not be confused with 'arthropod'; anthropods are humans or humanoids and do not moult in the canonic sense.
exoskeleton, chitin, molting
This is how they grow. The old exoskeleton splits, then the body expands rapidly before the new exoskeleton hardens.
the outter skin. as the arthropod grows, the outter skin doesn't grow with it. than it gets rid of it by molting!
Molting is beneficial because it allows animals to shed old feathers, exoskeletons, or skin, which can help in removing parasites and damaged tissues. It also enables growth of new feathers, exoskeletons, or skin, which is necessary for physiological functions and survival. Lastly, molting can help animals adapt to changing environmental conditions by allowing for improved insulation or camouflage.
Molting
Molting
Molting limits an arthropod's size because the process involves shedding the exoskeleton to allow for growth, which temporarily leaves the animal vulnerable. During molting, the arthropod must expand its body before the new exoskeleton hardens, making it susceptible to predation and environmental hazards. Additionally, the need to produce a new, larger exoskeleton imposes physical constraints on growth, as the structure must be strong enough to support the organism. Consequently, these factors can restrict the maximum size that arthropods can achieve.
Its new exoskeleton is soft.
Molting