Dead Bed Bug Shells and Casings

Bed bugs are some of the most psychologically disturbing insects that can infest your home. A nightmare!

They give their victims sleepless nights and few options, and are quite challenging to get rid of. Moreover, they leave behind brown shells and casings as they roam across your bed and home as the infestation progresses. 

So what exactly are these dead bed bug shells and casings

A bed bug shell and casing are similar, although they bear different names. As in other insects, bed bugs also have external skeletons known as exoskeletons which support and protect their bodies.

To help you get a better understanding, this article looks at:

  • The source of bed bug shells and casings 
  • The life cycle of bed bugs
  • How to identify bed bug casings

So let’s take a look at what it means when you see dead bed bug shells and casings and what to do about it.

A Bed Bug’s Life Cycle

When a bed bug nymph emerges from an egg, it will begin to seek its first meal of tasty, tasty blood.

The nymph will then molt five times during various life stages as it matures into adulthood. Molting is the process where it sheds its exoskeleton to allow it room to increase in size before growing another exoskeleton. 

A bed bug will shed its exoskeleton five times in its life cycle.

With every exoskeleton shed, a casing is left behind, and the nymph advances to its next stage. When the bed bug reaches adulthood, it ceases molting and stops growing.

Because the sizes of casings or shells vary, many people assume they are the exoskeletons of adult bed bugs.

However, at different stages, one can see the casing from a nymph or eggs. 

What Is a Bed Bug Casing?

Bed bug casing is a term used to describe a bed bug’s shell, particularly after it has been shed. The casing (exoskeleton) has to be periodically shed since the insects outgrow their skin as they mature. 

After mating, a female bed bug lays up to five eggs daily, each forming a nymph that hatches in approximately ten days. The eggshell left behind following the hatch can be considered the first casing of the nymph.

The nymphs go through five stages of growth before becoming adults, with every transformation preceded by a fresh blood meal. 

The nymph will then leave behind a casing towards the end of every stage. Upon reaching adulthood, the nymph stops increasing in size, and the shedding of the exoskeleton also stops.

Therefore, the casings you might find have been left behind in the various growth stages of the nymph. 

Nymph Stages and the Casing Size

  • 1.5 mm long casing – 1st stage nymph
  • 2 mm long casing – 2nd stage nymph
  • 2.5 mm casing – 3rd stage nymph
  • 3 mm casing – 4th stage nymph
  • 4.5mm casing – 5th stage nymph

The bed bug becomes increasingly darker after the shell is shed at various stages. And on becoming fully mature, it attains a dark reddish-brown color. 

Common Places To Find Bed Bug Casings

Bed bugs tend to live in groups, so finding many casings will be indicative of a substantial infestation. The locations where one is most likely to come across bed bug casings are around and in sleeping areas, particularly the folds, seams, behind headboards, box springs, or mattress crevices, as well as small cracks in the floorboards, in the walls, etc. 

Do not be misled by the name ‘bed bug’. There is an equally high probability of finding them in other areas, not just the bed!

They are likely to be found on:

  • Clothes
  • Furniture
  • Crevices or cracks in wooden molding
  • Stuff stored under the bed
  • Beneath loose wallpapers
  • Sofas, upholstered chairs, and recliners
  • In bookbinding
  • Ceiling-wall junctures
  • Inside TVs, smoke detectors, and clocks

Do not be misled by the name ‘bed bug’. There is an equally high probability of finding them in other areas, not just the bed!

One common misconception is that buildings or homes harboring bed bugs are unsanitary. This is false as bed bugs are likely found in pristine, daily cleaned hotel rooms.

They’re not present because of filth. They’re present because of blood. Tasty, sweet, delicious blood.

If you come across a bed bug in your house, the best thing to do is seek the help of pest control experts. Yes, you can try to tackle the problem yourself. But it’s a long, frustrating process, so be prepared. Professionals can develop an effective treatment plan for the bugs. 

Identification of Bed Bugs

Bed bugs are tiny vampiric insects about the same size as apple seeds. They are usually brown with oval and flat shapes. The bugs are classified together with ticks as parasites and feed on blood. Bed bugs swell to significantly large sizes on feeding, which prevails for about ten minutes. 

Bed bugs are tiny vampiric insects about the same size as apple seeds.

The pests are challenging to eliminate because they can go for months without feeding. Under the right circumstances, a bed bug can survive for months without having a meal. Furthermore, the bugs are resilient to most of the available products. 

To further worsen the situation, female bed bugs lay hundreds of eggs in their lifetimes. They also begin to reproduce just a month later and lay eggs three or more times annually. 

If someone suspects they might be having a bed bug problem, they should look out for the signs below:

  • Dark spots on the mattress or bedding that bleed onto fabric like marker pens. This is bed bug feces
  • Reddish-brown or rusty spots on sheets as a result of crushed bed bugs
  • Bed bug shells or casings
  • Tiny, white eggs usually laid in the seams of mattresses

Why Bed Bugs Shed Skin

A bed bug will shed its exoskeleton or skin in order to grow. The molting process is common to many insects during maturity as it transforms into an adult from a nymph.

As the bed bug molts, it will shed its exoskeleton and leave it behind.

Failure of the bed bug to molt will mean it will not grow, and thus will not attain adulthood. 

1. When Will a Bed Bug Molt?

A bed bug will shed its exoskeleton five times in its life cycle. Every stage brings the bug closer to maturity into an adult capable of reproducing and stops shedding the skin once it reaches adulthood. 

Young bed bugs, aka nymphs, tend to shed their exoskeleton shortly following their first blood meal. This is because the young bed bug requires the amino acids and protein found in human blood after every molt. 

Before molting, a bed bug will grow a new exoskeleton beneath its current one, although the exoskeleton remains weak for a time after they shed.

One can recognize bed bugs that have recently molted by their color. A bed bug with an exoskeleton that is more than a few days old will typically be dark brown or light brown. 

How Frequently Will a Bed Bug Shed Its Skin?

Bed bugs tend to shed their skin every seven to ten days during its maturation period. Weather can also influence the frequency of shedding the exoskeleton. During high temperatures, the bed bugs will molt faster than when it is cold.

A bed bug will molt every three to five days assuming a constant food supply and warm temperatures. 

It is common for a non-adult nymph, like one in its fifth instar stage, to be confused with an adult bed bug. Nonetheless, as a rule of thumb, a molting bed bug is still yet to reach adulthood. 

What To Do If You Find Bed Bug Casings

Since they are very small in size, it is almost impossible to see one nymph or bed bug egg. Nonetheless, spotting them where they occur as a cluster is easy. And since bed bug casings’ presence lasts for over one month, one will have plenty of time to make arrangements on how to eradicate them. The secret is to begin where there are many of them. 

Research has shown about 85% of bed bugs, and their casings or shells occur close to or in the bed. Remember, the bloodsuckers will not go away independently and quickly reproduce. People should act immediately if they find casings or shells in the living space.

Below are important measures to take:

Removal of bed bugs and their casings from mattresses

Note: it’s often easiest to just toss the mattress, if you haven’t spent a ton on it.

  1. Vacuum the box springs and mattress. Where there is a dust cover, take it off and check for more bed bugs below the box spring.
  2. Cover the box springs and mattress adequately to prevent the bed bugs left behind from escaping
  3. Take the vacuum outside the house and take off the vacuum bag
  4. Wash the box springs and mattress using boiling water and allow them to dry at noontime in direct sunlight. Let them dry for at least half an hour if there is no sunlight. 
  5. If applicable, remove the bed from the bedroom and have it cleaned outside
  6. When using an insecticide, spray the bed bugs directly. They will otherwise crawl away and return later
  7. Spray on the headboard and bed frame. There is a great possibility of bed bugs hiding in the crevices of wooden bed frames. Use a magnifying glass or flashlight if necessary
  8. For headboards attached to walls, remove and spray them and on the wall
  9. Dismantle wooden beds. The bugs prefer hiding in wood than metal
  10. Also, spray on the screw holes and screw heads
  11. Seek the intervention of professional pest control services if the infestation worsens


Bed bug casings and shells are identical, although their descriptions may differ. And because they are insects, they have exoskeletons that they need to shed for growth. A molted bed bug exoskeleton is called the bed bug casing or shell. 

After bed bugs mate, the female lays eggs in small spaces. The laid eggs hatch after approximately ten days and transform into nymphs, leaving egg casings behind.