Bat Bugs Or Bed Bugs? The Difference Decides Where The Work Goes

Bat bugs and bed bugs look the same to the naked eye and bite the same way. The difference is where they live. Bed bugs live with people. Bat bugs live with a bat colony, usually in an attic or a wall void, and they come looking for a person only when the bats are gone. Ohio State University Extension says separating the two takes a microscope.

That matters because the two jobs point in opposite directions. Bed bug work happens in the rooms people sleep in. Bat bug work starts above the ceiling, because the thing feeding the population is still hanging in the rafters. Iowa State University Extension is direct about the order of operations in its 2023 note on the subject: get the identification confirmed before any treatment begins.

Can You Tell Them Apart By Looking?

No. Both are flattened and oval, brown to reddish brown, roughly five millimeters long as adults, with small stubby wing pads that do not work, which is the description Ohio State University Extension gives in its bed bug fact sheet. The fact sheet lists bat bugs, chimney swift bugs and swallow bugs as relatives that get mistaken for bed bugs, and says a microscope is needed to examine the insect for the distinguishing characteristics, which often requires the skills of an entomologist.

Under that microscope the test is quick. It is the fringe of hairs along the edge of the pronotum, the shield behind the head. Iowa State University Extension describes bat bug hairs as longer than the width of the eye and bed bug hairs as shorter than it, and says that feature alone is usually enough to separate the two. The University of Tennessee Extension words its version the same way, with bed bug hairs shorter than the width of the eye.

How often does this actually catch people out? Iowa State reported in July 2023 that the majority of suspected bed bugs sent to its Plant and Insect Diagnostic Clinic that year were identified as bat bugs. That is one state and one clinic, and it reflects what people bothered to send in rather than what is in every house. It still says something about how confidently a household can name the insect from a photo on a phone.

Sources for the table: Ohio State University Extension on the look alikes, Iowa State University Extension and the University of Tennessee Extension on the pronotum hairs, and Colorado State University Extension on the hosts. If you catch one, keep it. Ohio State's guidance on submitting insect specimens asks for a vial of alcohol with a leak proof lid, isopropyl rubbing alcohol being the usual choice. A squashed insect on a tissue is a harder identification than a whole one in a jar. Our guide to checking a room for bed bugs covers what else turns up in that search.

Why Bat Bugs Show Up On The Top Floor

Because they are tracking a roost, not a sleeper. Colorado State University Extension says bat bugs are found most commonly on the upper floor of a building, where they sit closest to the bats, and that they reach the living space through cracks around light fixtures, attic hatches, the edges around vents, gaps at windows, the chimney and open holes in drywall.

So the pattern on the floor of the house reads differently than a bed bug problem does. Bites in an upstairs bedroom with nothing in the mattress seams, insects turning up near a ceiling fixture or an attic door, and nobody downstairs reporting anything, that is a shape worth taking seriously before the mattress goes to the curb. The bed bug inspection is where that gets settled, because the evidence a bed bug leaves on a bed is specific and either it is there or it is not.

Why The Biting Can Get Worse After The Bats Leave

Because the bugs do not leave with them. Colorado State says that when bats migrate in the fall, most bat bugs stay behind in the area where the bats had roosted, while some move about once their hosts have vacated and wander into living areas. Activity in the rooms below rises at exactly the moment the attic goes quiet, with a lot of insects looking for an alternative blood meal. The University of Tennessee describes the same thing after a colony is found and excluded, and after bat pups start to fly.

That is why a household often gets the timeline backwards. The bats went, the bites started, so the bats must not have been the cause. They were. And the wait is long: Colorado State says adult bat bugs are highly resistant to starvation and normally suspend feeding for seven to eight months when their hosts are not present, while Iowa State warns that bat bugs can live for months or longer without bats, so removing the colony does not clear the insects right away.

The good news sits in the same paragraph of the Colorado State fact sheet. Bats are the only host these insects can develop and reproduce on, so in the extended absence of bats, bat bugs eventually die off. The population has an end date. It is just not this month, and seven or eight months is most of an Ohio winter.

In Ohio, The Bat Half Is Regulated, And The Window Closed On October 15

The Ohio Department of Natural Resources handles bats through exclusion, a one way device that lets them out and not back in, and it sets two restricted periods around that. One runs May 16 through July 31 when five or more bats are present, to protect flightless pups and to keep mothers from pushing into living space trying to reach them. The other runs October 15 through March 31 whenever any bats are present at all.

During a restricted period, exclusion requires written permission from the chief of the Division of Wildlife or a designee. ODNR says that will be considered where human health and safety are at risk, or where nighttime temperatures exceed 40 degrees Fahrenheit for a full ten day forecast during the October dates. The workable windows it names are April 1 through May 15 and August 1 through October 15. Penn State Extension gives the same shape of advice for the Northeast generally: bat proof in early spring before the bats arrive, or in fall after they have gone.

There is a second rule behind that one. Wild animal control in Ohio is a separately licensed trade, bat exclusion included, which is why it sits outside a pest control plan. We went through that line in detail in our post on what a quarterly plan does not cover.

What There Is To Do Before April

Quite a lot, as it happens, and none of it is the thing people reach for first.

• Get the insect named before anything is treated. Iowa State is explicit that identification should come first and that a physical specimen beats a photograph for something this small.
• Close the routes between the roost and the rooms. Colorado State says any method of sealing off the bat roosting area from the human living space helps prevent these migrations, and it names the usual paths: light fixtures, attic hatches, vent edges, window gaps, the chimney, holes in drywall.
• Leave the droppings where they are for now. The CDC and NIOSH guidance on histoplasmosis is built around not raising dust from bat or bird droppings, and says that simply leaving the material alone may be the best course where human activity around it is unlikely. Where removal cannot wait, it describes an industrial vacuum with a high efficiency filter and sending large accumulations to a company that handles hazardous waste.
• Skip the gadgets. The same CDC guidance states plainly that ultrasonic devices and chemical repellents are not effective for eliminating bats from a roosting area.
• Book the exclusion for the spring window rather than hoping it resolves itself, and have the attic looked at by someone licensed for wildlife before the April date arrives.
• Keep sleeping where you sleep. If the identification comes back as bed bugs instead, moving to a couch or a spare room spreads them, and if it comes back as bat bugs, the bedroom was never the source in the first place.

Which Half Of This Is Ours

The insect half. An inspection settles whether what is biting is a bed bug, a bat bug or something else that gets blamed for bites, and that answer changes who you call next. If it is bed bugs, our ThermaLock heat treatment takes the whole room to a lethal temperature and holds it there, which kills every life stage including the eggs, usually in a single day and with no chemical residue. The inspection fee is waived when you go with us for treatment.

If it is bat bugs, the honest answer is that the colony overhead is the job, and in Ohio that is licensed wildlife work on a calendar the state sets. Knowing which of those two you are dealing with, in October rather than in April, is worth the trip on its own. Call 330-494-6199 or schedule an inspection and we will start with the insect in the jar.