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Bed Bug Confidential: An Expert
Explains How to Defend against the Dreaded Pests
Everything
you ever wanted to know about bed bugs but were afraid to ask
By Kate
Wong | Monday, January 23, 2012
Image: Armed Forces Pest Management Board
Chances are, you
or someone you know has had a run-in with bed
bugs. It might have happened in a scrupulously clean bedroom. Or
maybe it was a hotel room, office or college dorm. In the February
issue of Scientific American entomologist Kenneth Haynes
of the University of Kentucky explains how, after a lengthy absence, bed
bugs are staging
a comeback. The good news is scientists are intensively studying
these insects, and their insights suggest novel ways of detecting the bugs
and eradicating infestations. Some of those potential solutions are a long
way off, however. In the meantime the best bet is to avoid bringing bed bugs
home in the first place. I called Haynes to ask him how to do that and what
to do if one suspects an infestation (eek!), among a bunch of other
practical-minded questions.
Do bed bugs only
feed on humans?
No. Bed bugs are also pests in poultry operations, and they're known to
parasitize bats. Some labs that study bed bugs rear them on guinea pigs and
mice. The bugs might feed on cats and dogs. Fur is probably a barrier to
them, but they could feed at any place on the body without fur. Bed bugs are
not specific to humans, but they are adapted to parasitizing us.
Could you have a
bed bug infestation in your home and not know it?
That's very
possible. I have heard of couples reporting that only one partner is getting
bitten. The truth is that both are getting bitten, but only one has a
reaction to the bites. Thirty percent of people or more don't react to bed
bug bites at all, and the elderly are less reactive than the rest of the
population. Among those people who do react to the bites, most of them don't
respond to early bites, but develop a sensitivity to subsequent ones. Those
individuals who are not sensitive to bed bug bites may not know they have an
infestation. Because bed bugs are nocturnally active, it's hard to see other
signs of their presence—unless you're accustomed to waking up at 3 A.M. and
taking a census. With a huge infestation, bed bugs start to move away from
the bed, so you're more likely to see one in an exposed place during the
day. In very severe infestations people can become anemic. That takes a lot
of bugs though—maybe 100,000 feeding once a week or more.
Another
clue to infestation is odor. Like many species of bugs, bed bugs release
odors called alarm pheromones. When a group of bed bugs gets disturbed, you
may get a whiff of that odor, which is similar to the odor stink bugs give
off. At higher concentrations the odor is unpleasant. Some people say at low
concentrations it's a pleasant smell—like coriander. In fact, older
literature refers to the bed bug as the coriander bug. I've tried to smell
the coriander scent in bed bug alarm pheromones and have not been able to
make the connection, however.
What can one do
to avoid getting bed bugs?
The first thing is you have to be able to recognize and distinguish a bed
bug from any other insect. Everything starts to look like a bed bug if you
start to worry about them. An adult bed bug is about the size and shape of
an apple seed. If it has not fed recently it will be flattened and brown. If
it has fed it will be round in circumference and reddish. Immature bed bugs
have a similar appearance to adults, with the smallest being the size of the
head of a pin. You can then learn to look for their fecal spots, which can
be easier to detect than the bugs themselves. Check your hotel rooms when
you travel. And think twice before bringing home used furniture. If you are
purchasing used furniture, ask the furniture store how they deal with bed
bugs. If they have no plan whatsoever, that's probably not a good sign. If
you purchase used clothing, put it through a clothes dryer on a medium to
high setting for a cycle as soon as you bring it home. And before you move
into an apartment, ask the landlord whether there has been a bed bug
infestation, or whether the building has ever been treated for bed bugs.
What should one
do upon suspecting a bed bug infestation
The first
question I would ask that person is, what makes you think you have bed bugs?
A skin reaction alone does not necessarily indicate the presence of bed
bugs. Other bugs, allergies and irritants in the environment can produce
similar skin reactions. And it's hard to confidently identify a bed bug bite
because reactions vary from person to person. My next question would be,
have you seen an insect in an area where you sleep and, if so, was it the
correct size and shape to be a bed bug? Carpet beetles in an immature stage
are commonly mistaken for bed bugs. The carpet beetle actually doesn't look
anything like a bed bug, but it is the right size. And it's another common
insect to have indoors around the bed. If you find an insect that you think
is a bed bug, save it in a pill bottle or another container so its key
characteristics won't get crushed and a professional can identify it.
I wouldn't
try to get rid of an infestation on my own. I would call a pest control
operator. A good pest control operator will spend a fair amount of time
inspecting the place for evidence of bed bugs, and will educate the person
on what makes it clear that it's a bed bug infestation.
Once you
have a suspicion or a confirmed infestation, do not spread things outside of
the bedroom. Don't take linens off the bed and go to sleep somewhere
else—that will just move the infestation to other rooms. Ultimately pest
control operators will tell you to put everything you can through the washer
and dryer, since bed bugs cannot withstand high temperatures. I don't think
bed bugs would be able to survive solvent-based dry cleaning, but I don't
have any first-hand knowledge that that's true. Unfortunately, dry cleaners
and Laundromats can be places where people pick up bed bugs. I think it's a
low probability, but it only takes one adult female bed bug that has been
mated to get an infestation going.
The safest
and most effective approach to getting rid of bed bugs is heat treatment, in
which a trained professional heats the home's rooms one by one to a
temperature of 50 degrees Celsius and sustains the heat for four hours. Heat
does not penetrate well into wall voids, though, so desiccant dusts are
often applied to those areas. No single technique can eliminate bed
bugs—combinations of approaches are essential to getting the job done.
What are the
mistakes people make in trying to get rid of bed bugs on their own, without
professional help?
DIY approaches come with risk. It's not uncommon for someone to use a
pest-control bomb or fogger that is available over the counter. These don't
work well against bed bugs, according to research from Ohio State
University. They can also expose people to toxic chemicals. Neither are
over-the-counter aerosol insecticides effective against bed bugs. Most of
these products have either pyrethrin or a pyrethroid as a main ingredient
and those compounds have the same mode of action as DDT, which bed bugs have
become resistant to. If you spray the bug directly you might kill it, but
that is not going to get rid of the infestation. The problem is finding all
the bed bugs. Some just can't be reached with insecticide. It's difficult
for nonprofessionals to do anything more than kill what they can see, but
that's just the tip of the iceberg in terms of what's there.
Some of the
dusts that are available to consumers, such as diatomaceous earth, can help
in this regard. Pest controllers will put dusts in wall voids and other
places where pesticide won't reach. What happens is the bugs will wander
through the dust and pick up particles and be more vulnerable to desiccation
after that exposure. But dusts will not solve the problem if deployed
incorrectly, and if they are applied at too high a level they can cause
breathing difficulties in some people.
The
Internet abounds with so-called miracle cures for bed bugs. But bed bugs are
hard to get rid of, so anything that advertises an immediate solution is not
accurate—it's snake oil. These "cures" have included (as reported by pest
control operators who come in afterward to tackle bed bugs correctly) using
bleach, ammonia and even DIY heat treatment, which carries fire risk.
Another
solution you hear about is vacuuming. You can vacuum up a lot of insects,
but eggs are harder to get, and vacuuming won't in and of itself kill bed
bugs. Indeed, vacuuming can end up spreading bed bugs to other rooms—when
emptying the canister, for example. Pest control operators who use vacuums
take measures to prevent bed bugs from escaping when the vacuum is emptied.
Encasing
mattresses is one of many good parts of a solution, but it doesn't get rid
of the infestation. There are going to be other bugs away from the mattress,
hiding nearby. What mattress covers are good at is entombing the sometimes
large number of bed bugs that can live on a mattress. And because the covers
tend to be uniform in color and don't have a lot of seams that the bugs can
hide in, it's easier to see the insects.
Given that you
work with bed bugs, how do you avoid bringing them home?
I have four risk factors. I work with bed bugs in a lab situation, so we
have to take extreme precautions to prevent escapes there. I visit infested
apartments sometimes. I travel a fair amount, so I may be exposed to bed
bugs in hotels. And I've had college-age kids, who can bring bed bugs home
from dorms.
In the lab
we handle all the bed bugs in a specific room that we steam clean once a
week, and we have double-stick tape barriers that they can't walk through
(as long as the adhesive remains dust-free). And the bed bugs themselves are
enclosed in containers that they can't get out of. We actually feed them
inside those containers—we lay a blood reservoir against the cloth "lid" and
the bed bugs have to push their mouthparts through the cloth into the
reservoir to eat.
If I go to
an infested apartment, then when I leave I check my shoes very carefully for
bugs that may have crawled onto them. I also keep a change of clothes in my
garage and put them on before entering my house. Once inside, I immediately
put the clothes I wore to the infested apartment in the dryer, which is
located in a room just off the garage.
When
staying in a hotel, I check the bed before I bring the suitcase into the
sleeping part of the room so that if I have to ask the manager for another
room, then I haven't exposed my suitcase to the bugs. When settling in, I
put my suitcase up on the suitcase stand or the desktop so that any bugs are
less likely to crawl into it. An extreme measure would be putting the
suitcase in the tub. If it's a porcelain tub, bed bugs would have a hard
time crawling up it. It's also unlikely that they would randomly crawl up a
tub, because it's not near the bed. But if I don't see bed bugs in the room
when I inspect it, I just put my suitcase on the stand because I know the
probability is really low that a bug is going to crawl up the stand and into
my suitcase. I keep my clothes in the suitcase or hang them in the closet—I
don't leave them on the floor because wandering bed bugs might crawl into
them.
I actually
haven't found bed bugs in my hotel rooms, but I've seen them in other
peoples' rooms. Enough of my students and postdocs have found them that I'm
surprised I haven't seen them yet in a room where I'm staying.
How should one
check a hotel room for bed bugs?
Bring a little flashlight—hotel room lighting is always pretty poor and the
dimmer the lighting, the harder it is to see small bed bugs or their fecal
spots. I would pull back the bed covers and look all around the head of the
bed. Pull back the sheets, too, and look at mattress seams and edges that
are exposed. bed bugs love to hide under mattress tags. Look all around the
box springs, too. If there's a dust ruffle, pull it up and look under it as
much as possible. Look for moving bugs and stationary, hiding bugs.
The space
behind the headboard is prime bed bug territory. Most headboards are hanging
on the wall. If my wife is with me, we'll remove it and look behind it. This
exposes a lot of possible bed bug territory. Even if you don't remove
headboard, look around it. Or if you move the bed out from wall, look at the
wall under the headboard.
Bed bugs
could also be at the foot of the bed, but they're more likely to reside at
the head of the bed. The foot of the bed, if the sheets are tucked in,
doesn't allow bed bugs easy access to a sleeping host. The bugs would have
to come up to the head of the bed to get you, and they typically minimize
the distance to the host.
All of the
stages of bed bugs are visible, at least if you don't need reading glasses
and you have a sufficient amount of light. So if you're looking closely
enough, you can even see bugs in the nymphal first instar stage. A fecal
spot, for its part, can be as large as a bed bug itself in terms of the area
it covers. The spots are basically digested blood, so most are dark in
color. On a white mattress, they stand out pretty well.
Are there tactics
that professional exterminators use that don't work?
No one tactic alone will be effective. A good pest control operator will
develop a strategy to deal with the bed bugs that takes the particulars of
the setting into account, and will return several times to check on
progress. Dry ice sprays that freeze bed bugs have limited potential to
reach hidden bugs. Steam has somewhat better penetrating ability. The
downside of steam is that it leaves moisture behind. Dry ice doesn't leave
any residue at all. Vacuuming has a role, but it has limitations, too. Some
insecticides leave behind deposits that are slow to act but are effective in
the long-term. Other insecticides kill on contact, but only reach insects
that are in view. Insecticide resistance makes the choice of tactics more
difficult.
An important
thing to remember is that good professional pest controllers do get rid of
bed bugs. The fine line that bed bug experts have to walk in talking to the
public is the line where the anxiety and depression and so forth that can
result from thinking about bed bugs too much can cause more problems than
the bugs themselves would. |