School Pest News Volume 10, Issue 8


Section 1 Crazy ants making tracks through South Central Texas. 1

Section 2 IPM and IAQ inspections can find open floor and wall penetrations. 2

Additional Information – University of Florida – Tight Spaces. 3

Section 1 Crazy ants making tracks through South Central Texas

Travis County is one of the most recent areas of Texas to be invaded by crazies – in this case, Caribbean or Rasberry crazy ants, said entomologists with the Texas AgriLife Extension Service.

Crazy ants get their name from their erratic movements as they do not trail in a straight line, but rather in a random pattern, the experts said. They are small, black ants with long legs and antennae, and upon first glance may resemble tiny spiders.

“Crazy ants don’t sting and they’re not really a health hazard in that they’re not a disease vector,” said Wizzie Brown, AgriLife Extension integrated pest management specialist for Travis County. “They’re basically an outdoor ant, but in their search for warmth, water, or food, they often come indoors.”

Brown said confirmed crazy ant identification in Travis County has been from the northwestern part of the county, near where Travis and Burnet counties meet.

She said once crazy ants find their way into a home it is easy for them to multiply and spread to different areas, especially into bathrooms, kitchens, and pantries.

“Although not harmful, crazy ants can certainly be very annoying, especially if they get into your food or invade your house in large numbers,” she said.

The main problem with crazy ants, she said, is that they just won’t go away.

“Once they have invaded an area, you will hardly ever hear about them leaving on their own accord,” Brown said. “They have a very high reproduction potential and tend to stick around.”

Crazy ants were already discovered in nearby Bexar County earlier this year, so residents there have been aware of them for several months.

“We’ve even had crazy ants at the AgriLife Extension office here in San Antonio,” said Molly Keck, AgriLife Extension integrated pest management specialist for Bexar County. “I’ve gotten calls from people all over the county saying they have them, but so far they really haven’t taken hold in any particular residential area.”

Keck said crazy ants love concrete, so sidewalks, driveways, or paved areas around the home provide them with an excellent habitat.

“To manage crazy ants, try some basic integrated pest management practices first,” she suggested. “Seal and caulk up small cracks and holes around windows and doors. Remove trash, leaf litter and other debris from near the house and keep food well hidden and off the pantry floor. Trash piles, discarded papers or magazines and cardboard are some favorite places for crazy ants to nest.”

Keck said chemical control is limited and there are few, if any, effective organic options.

“Barrier sprays around the foundation of the home and long concrete pathways are reasonably effective,” she said. “And indoor sprays at entry points may also keep them at bay. However, these are only temporary and will not permanently control crazy ants.”

For large quantities of crazy ants, both Keck and Brown recommended calling a pest control professional.

“You can manage small numbers of ants adequately with spray or barrier pesticides rated for ants,” Brown said. “But these control methods are less than effective against large ant populations, especially if they keep spreading to new areas.”

“You’re better off having pest control professionals managing large crazy ant populations because they are more experienced with pesticide mixtures and treatments,” Keck added. “Ultimately professionals tend to use far less pesticide than non-professionals.”

Both experts also noted that if county residents need help identifying a particular ant species, they may bring samples of the ants to the AgriLife Extension office in a closed baggie or small container with a well-fitting lid.

Brown can be contacted at 512-854-9600 or, and Keck at 210-467-6575 or


Section 2 IPM and IAQ inspections can find open floor and wall penetrations

When a Facility Director receives complaints from teachers, staff, principals and others it leads to some type of investigation or inspection.  Investigations into indoor air quality (IAQ) complaints have revealed several cases where the IAQ of a classroom, staff office, or school building was adversely affected by an open and unsealed pipe penetration through a floor, wall, or ceiling of the building.  The next time you have an unknown problem consider these situations.

In each case, occupants of the classroom were experiencing an adverse reaction to an unknown airborne irritant that was not identifiable by visual traits or normal IAQ tests.  The occupants reported their concerns to the school administrator who contacted an IAQ consultant to conduct a building investigation.  In each case, the investigation revealed that an open floor or wall penetration was hidden from view.  The penetrations were either above a suspended ceiling, in an enclosed chase, behind cabinetry, or hided by a counter or other classroom furnishings.

During construction or renovations, the penetrations were made for passage of a pipe, conduit, or duct through an exterior floor or wall but were left unsealed due to insufficient construction funds to pay for proper sealing of the wall or floor opening.

In some cases, the penetration was for an abandoned building system but in most cases, the penetration was formed during the installation of a new building system.

The opened and unsealed penetration allowed contaminated exterior air to enter the interior space and the building’s HVAC air conveyance system.  The infiltration of this unconditioned air carried water vapor, particulate matter, gaseous odors, and infectious microbes into the school building.  The infiltrated water vapor increased the interior relative humidity and led to mold development or other microbial activity.  Airborne particles, gases, and microbes increased the adverse health effects of the classroom students and teachers.  In many cases, the unconditioned air was coming from a basement or crawl space with an earth or dirt floor.  Some openings were large enough for small rodents, skunks, or raccoons to enter the classroom.

School construction and renovation activities must include sufficient funding to properly seal these floor and wall penetrations during the construction phase.  If they are not sealed at this time, the costs to seal them will go up higher, since walls or furnishings that have to be removed to gain; access for the repair will require additional labor costs after the fact.  Once corrected these additional sealing procedures of these penetrations can improve the thermal efficiency of the School’s Heating and Air Conditioning system and save dollars from the district’s energy bills.  Funds for sealing penetrations in walls and floors must be included in the total school construction budget and should be considered before not after a new project is started.

This information is not complete without some vital images – Penetration images that can cause pest and odor problems to see the images most often found once the problem has been diagnosed.  Remember when you are conducting a school IPM inspection; there ARE areas that you should note as well on an inspection sheet.

Additional Information – University of Florida

Know the Facts: 90 years of tight spaces

  • The association between tight spaces as cockroach harborage has been known for over 90 years.
  • In 1975, Walter Ebeling, the father of urban entomology, wrote a textbook where he referenced a 1920 publication by Wille.
  • Ebeling credits Wille with determining that adult German cockroaches can “move about in space only 1.6 mm in width or depth.”
  • How much is 1.6 mm? 
    • About 0.06 inches, which is virtually meaningless to me.
    • However, my UF credit card is almost 1 mm thick.
    • So 1.6 mm would be just shy of the thickness of two credit cards.

Emphasis on clutter and sanitation

Why de-clutter?  The virtues of de-cluttering are endless:  eliminate breeding sites, increase ability to treat and most importantly, de-cluttering will help with all-important inspections and monitoring programs!

Does sanitation really improve treatment results?  We have a number of excellent cockroach products, particularly baits, but their efficacy can be compromised because of poor sanitation.  Sanitation includes de-cluttering and the removal of competing food sources, which will improve your treatment results.  Additionally, cleaning surfaces appropriately (soapy water with water rinse) will help remove grease that can compromise the effectiveness of some products as well as remove allergens deposited by cockroaches, which are known triggers for asthma.

Finally, cleaning surfaces of fecal spots will also remove pheromones will are responsible for cockroach aggregations.  The gregarious behavior of German cockroaches in association with pheromones has been recorded as early as 1945 by Ledoux.

For more information about school IPM, go to  

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