Bed Bug Cast Skin: How Does It Benefit Humans?

Bed bugs grow through 6 different growth stages and they do these by molting. Bed bug cast skin during molting, and this is very important because it helps them grow out of their rigid exoskeletons.

You will find out in this article that bed bug cast skin is actually beneficial to the bed bugs and even we their hosts.

Sounds absurd, right? Let us now find out how this will benefit us!


Do Bed Bugs Cast Skins?

Bed Bug Cast Skin
Molting Is a Common Process Amongst Insects

All insects have exoskeletons, and since the bed bug possesses the attributes of an insect, it is therefore an insect and hence has an exoskeleton.

Do bed bugs cast their skin? Yes, they do. Bed bugs, like most insects, such as roaches (some species) and spiders, shed their skins five times before they mature into adults, and molting is what this process is called.

We mentioned that bed bugs molt before they mature into adults, so this does mean that the shells you encounter represent a growing bed bug infestation.

Bed bug egg shells are white in color and oval in shape, with a length of 0.0625 inches. There is a slim chance of encountering this shell, as its size and color make it difficult to detect with the naked eye.

Another challenge you may come to face is differentiating the eggshells of bed bugs from those of other insects. Now this will be a challenge because if by chance you are lucky to spot an egg casing, you will not be able to tell if it belongs to a bed bug or another insect, and now controlling an infestation becomes uncertain.

This process is completely normal among insects (roaches, spiders, carpet beetles, etc.), so you should not expect that only bed bugs are capable of this act.


Read also: Can Bed Bugs Survive In A Dryer?: The Adult Bed Bug’s Immunity


What Does Bed Bug Cast Skin Look Like?

Bed bugs literally walk out of their shells, and in fact, they may be among insects that have a perfect molting. Their skins are like suits, and so they walk out of them. It will not even be a surprise if you see a bed bug cast skin with arms and legs complete.

Bed bug cast skin is most times like a bed bug itself, unless it lacks color and has no life in it. This therefore makes identifying the shell (not the eggshell) simple.

These suit-like shells are commonly referred to as exoskeletons, and as we mentioned previously, all insects possess this covering.

The essence of the exoskeleton is to protect the body of the insect from simple damage and enable movement through muscles attached to the inside.

It should be noted, however, that some insects (grasshoppers, roaches, spiders, etc.), have their exoskeletons more visible than others.

Molting is very important for bed bugs and other insects, as it enables them to grow and increase further. The exoskeleton is rigid and will prevent the bed bug from easy movement and growth, so the bed bug must grow out of it.

This growth is what entails the different (6) growth stages of the bed bug.


Why Do Bed Bugs Cast Skin?

Why do bed bugs cast their skins? Well, we have mentioned previously that they do this in order to grow. The process of molting is what constitutes their different (6) growth stages.

To us humans, it is important that they molt because it will help identify a pending infestation and help you keep them at bay.


Read also: Can Bed Bugs Survive In A Storage Unit?: Bed Bug Survival Chance


How Do Bed Bug Skin Cast?

As earlier stated, bed bugs cast their skins to outgrow their former skins (exoskeleton), and this growth is what constitutes their stages of growth.

How does a bed bug cast skin? Well, bed bug skin cast begins as the eggs hatch into nymphs. A nymph is the second stage of a bed bug’s lifecycle.

When they become nymphs, they now have to outgrow this stage 5 more times until they become adults. As adults, molting stops, and they can now grow further by feeding on human blood, increasing to time 2 of its size.

Are you looking to identify how extreme your bed bug infestation is? Then you do not have an issue, as these shells will help you know how far an infestation has gone, depending on the size of the bed bug casing.

Shell Growth Stage


Egg Shell

1 mm

1st Nymph Shell

1.5 mm

2nd Nymph Shell

2 mm

3rd Nymph Shell

2.5 mm

4th Nymph Shell

3 mm

5th Nymph Shell

4.5 mm

The nymph feeds for at least 11 minutes and has to feed on blood for each of its growth stages in order to grow. Of course, food is important for growth, and as food is important to you, so is blood important to bed bugs.

When these nymphs are feeding on your blood, do you know why you do not feel the bite? Well, this is something that even mosquitoes do; bed bugs have these anesthetics in their saliva that ensure you do not feel any pain when they are biting. This is why you sleep peacefully even when they are biting.

You must know that bed bugs will grow very fast under normal circumstances. These normal circumstances include:

  • Warm temperatures ranging from 60 degrees to 70 degrees.
  • Constant access to blood from an unsuspecting host.

Under these normal circumstances, they can molt every week and should become adults in 6 weeks. But when they are growing under conditions that do not favor them, their growth may ensue for 6 months.

Unlike other insects that live apart, bed bugs usually live in groups and this will make identifying their shells easy for you. If they live together, then it is pretty obvious that their shells will be close together instead of being scattered all over the house.

Finding a bed bug skin casting should not be difficult to find as they will be near their hosts. This means that you will find them around your beds and mattresses.


Where is the Cast Skin of a Bed Bug Found in the Home?

Bed Bug Cast Skin
You Will Find Bed Bug Cast Skin In Your Furniture

If you have read to this point, you should know where these bugs actually live in your homes. Below are possible places where you can find bed bugs:

  • Beds
  • Mattresses
  • Crevices
  • Furniture
  • Holes
  • Gaps
  • Wood


Read also: Can A Black Light See Bed Bugs?: The Power Of A Black Light



Bed bug cast skin is actually beneficial to the bed bugs and even you, the host. The bed bugs benefit because it helps them grow through their different stages, and humans benefit because spotting these molts will help us become aware of an infestation.

What do you think of the bed bug cast skin? Have you ever seen one in your home? Let us know via the comments section below.

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