What bugs look like bed bugs? A Dr. Killigan's insight


Spotting a tiny insect on your bedspread or lurking in your room can immediately bring to mind one alarming thought: bed bugs. However, while these pests are undoubtedly a cause for concern, many other critters can be easily mistaken for them. In this guide, presented by Dr. Killigan's, we will delve into the details to help you differentiate between bed bugs and their look-alikes. We'll discuss bat bugs, swallow bugs, booklice, carpet beetles, spider beetles, and even the young smoky brown cockroach nymphs. With this knowledge, you'll be better equipped to identify and deal with any unwelcome guests in your home.

Bat bug vs. bed bug: Unraveling the mystery

To the untrained eye, bat bugs and bed bugs can seem virtually identical. Both belong to the Cimex genus and possess an unsettlingly similar appearance. But when we delve deeper into their habits and preferences, clear distinctions emerge.

Bed bugs are infamous invaders, preferring the blood of humans as their primary meal. Their life revolves around human habitats – typically within close proximity to our sleeping areas. When bed bugs bite, they leave behind red, itchy welts and their persistence can turn our restful nights into endless itching sessions.

Bat bugs, true to their name, primarily feed on the blood of bats. The presence of these pests often indicates bats residing in attics, walls or other nearby locations.


If a bat colony relocates or is evicted, these bugs may wander, seeking other food sources, which can occasionally include humans. If you find a dead bat bug in your home, it might indicate that the bat colony they depended on has moved or is no longer present, increasing the likelihood of these bugs turning to humans as an alternate food source. While they can bite humans, it's not their first choice, and such bites are usually a sign of their primary food source being unavailable.

Swallow bugs unveiled: Moving beyond the bed bug resemblance

The name "swallow bugs" might bring to mind a creature with a specific preference, and that's precisely the case. These bugs have a close association with cliff swallows. Now, if you're wondering about cliff swallows and where they reside, let's shed some light on that.

Cliff swallows are remarkable birds, easily identifiable by their glossy, blue-black backs and pale, pumpkin-colored rumps. They are adept at constructing mud nests, typically on vertical surfaces.


In nature, they might opt for cliffs (hence their name), but in urban settings, these birds are often found building their nests under eaves, bridges and other overhangs. So, could they be in your backyard? Absolutely, especially if you have structures that offer sheltered nooks.

When cliff swallows make a habitat choice, swallow bugs aren't far behind. These bugs primarily reside in and feed off cliff swallows, making their nests a perfect home. However, sometimes, nature takes an unexpected turn. If cliff swallows vacate a nest or if their nests get disturbed, the now-displaced swallow bugs might start looking for alternate shelters and food sources. In such scenarios, they can venture indoors, and while they may bite humans, it's more out of necessity than preference.

For homeowners, and especially for us at Dr. Killigan's, understanding the connection between swallow bugs and cliff swallows is crucial. If you identify cliff swallow nests around your property, it's wise to be vigilant about the potential presence of swallow bugs. Properly identifying these pests ensures that you can adopt the right measures to keep your living spaces bug-free and comfortable.

Booklice in bed: Debunking the library dwellers myth

When one hears the term “booklice,” it's not uncommon to envision minuscule invaders sandwiched between the pages of one's favorite reads. However, despite their unsettling name and their passing resemblance to bed bugs, they're notably different pests.

For one, booklice are much smaller than bed bugs. While adult bed bugs are about the size of an apple seed, booklice often measure just 1-2 mm in length. Their coloration also differs. Booklice are typically pale, translucent or grayish-white and they don't turn red after feeding, unlike bed bugs which can redden once they've had a blood meal.


The body shape of booklice offers another distinguishing feature. They possess a more elongated frame, sometimes even appearing to have a "neck," while bed bugs exhibit a flattened, oval shape. Their habitats and diets further set them apart. While bed bugs are known to lurk in mattress seams and other bedroom crevices, feasting on human blood, booklice thrive in damp environments, munching on mold, fungi and starchy materials.

If you stumble upon booklice in your bed or bedroom, it may indicate underlying moisture issues, leading to mold or fungi—their primary food sources. Although they can be a nuisance, the silver lining is that they don't bite, ensuring you won't wake up with those telltale itchy red marks associated with bed bugs. 

At Dr. Killigan’s, our advice is straightforward: Address the root cause, usually humidity and mold growth, to fend off these deceptive library dwellers.

Carpet beetle vs. bed bug: Distinguishing the culprits in your home

At first glance, carpet beetles and bed bugs might seem strikingly similar, especially to the untrained eye. Their sizes are somewhat comparable, often leading homeowners into a state of confusion. But when you take a closer, more discerning look, these two pests are quite distinct in both behavior and appearance.

Carpet beetles are nature's scavengers. Their diet primarily consists of organic materials such as wool, silk, hair and even dead insects. Unlike the blood-hungry bed bugs, carpet beetles have no interest in feasting on human or animal blood. This difference in dietary habits often leads to distinct behavioral patterns.


While bed bugs tend to stay close to their human hosts – typically in mattress seams, box springs or bedroom crevices – carpet beetles are more often found around natural fiber sources, like woolen garments or upholstered furniture.

In terms of appearance, a few key characteristics set these two apart. Carpet beetles sport a more rounded or oval shape and can be quite varied in color. Depending on the species, they might have patterns of white, brown and even orange scales on their back. Bed bugs, on the other hand, are consistently brown, more flattened and have a distinct oval shape without any variations in coloring.

Understanding these differences is vital. While carpet beetles can damage your belongings, bed bugs can lead to sleepless nights and itchy, red welts. As always, with any potential infestation, it's essential to correctly identify the pest at hand to address the issue effectively and ensure peace of mind in your home.

Spider beetle in bed: Decoding the arachnid impersonator

When you spot a spider beetle in your bed, it's quite natural to feel a mix of confusion and concern. At a cursory glance, these little pests with their rounded bodies and elongated legs can eerily resemble both spiders and bed bugs, leading to understandable misconceptions. But understanding their unique characteristics is crucial in correctly identifying and handling them.


Unlike the parasitic nature of bed bugs, spider beetles are scavengers. Spider beetles primarily feed on grains, dried fruits, cereals and other organic materials. Unlike some pests, they don't seek blood meals at night; they're more apt to search for leftover food or invade pantry goods. This distinction in feeding habits is a reassuring sign that the nocturnal disturbances aren't due to another bed bug infestation.

When it comes to appearance, spider beetles boast a somewhat shiny, reddish-brown or golden-yellow hue, depending on the species. Their legs are notably more slender compared to bed bugs, and they possess a distinctively bulbous abdomen, giving them a spider-like appearance. If you're facing a spider beetle issue, the solution often lies in meticulous pantry management. Ensure all foodstuffs are stored in airtight containers and routinely check for old or forgotten food sources that might be attracting these beetles. Proper identification will guide the right preventative measures, ensuring a beetle-free, restful night.

Smoky brown cockroach nymph vs. bed bug: Deciphering the tiny trespassers

Stumbling upon a smoky brown cockroach nymph can be quite startling, especially when their size and shade can easily lead one to mistake them for a bed bug. However, armed with the right knowledge, distinguishing between these two pests becomes a straightforward task.

At the nymph stage, the smoky brown cockroach exhibits a sleek, elongated body, a departure from the typical appearance of its more mature counterparts. Their color ranges from a translucent tan to a deeper brown, often leading to bed bug confusion.


Yet, upon closer examination, you'll notice that their body structure differs from bed bugs. The nymphs have segmented bodies and, as they grow, will develop the characteristic glossy wings of the smoky brown cockroach.

Habitat and behavior further amplify these differences. While both are nocturnal, their preferred hideouts contrast starkly. Bed bugs, being parasitic, will often station themselves close to their human hosts, typically around bedding or sleeping areas. In contrast, the smoky brown cockroach nymph is attracted to moisture and decaying organic matter, making damp environments like kitchens, bathrooms, or basements their prime dwelling spots. Recognizing these distinctions is paramount not just for peace of mind, but also for implementing effective pest control measures tailored to the specific intruder.

Note: If you think you might actually have bed bugs, detection is key. Early identification can prevent a full-blown infestation, ensuring a swift and effective treatment. 

Conclusion: Your best defense against unwanted guests

Recognizing and understanding the myriad insects that can infiltrate our homes is the first step in effective pest control. With this knowledge, homeowners can tackle pest issues with precision. Dr. Killigan's is committed to ensuring you're equipped with the best. Six Feet Under is a non-toxic, fast-acting long-lasting spray designed to exterminate pests on contact, without harming your home environment. On the other hand, Dust to Dust is an eco-friendly powder that targets pests in those hard-to-reach nooks and crannies, ensuring they have no place to hide. It can also be used proactively. With these quality products at your side, you can make your home a true haven, free from the stresses and discomforts of unwelcome critters.

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