Ants VS. Roaches

As we have moved into the new millennium, baiting for cockroaches and ants has become the treatment of choice for many PCOs. The movement away from other pesticide treatments has grown throughout the past 10 years. At industry tradeshows, as well as at professional scientific meetings, we have witnessed a blossoming of bait products.

University researchers and professionals have studied the behavior and biology of both pest species to better understand their "nutritional needs." This knowledge has been transferred to bait manufacturers who have answered the call for better-designed baits. They have designed bait bases that roaches and ants readily consume containing highly advanced active ingredient systems that effectively kill target pests with small doses of insecticide. In turn, the modern PCO is armed with some of the most technologically advanced products and delivery systems available to attack pest roaches and ants.

In the beginning of the "bait boom," cockroaches were by far the more popular of the two pests. Most of the development and effort to create better baits was focused on cockroaches. In the last few years the popularity — and some say incidence — of roach infestations has dwindled. We now have a new pest that has entered the limelight — ants.

The bait manufacturing industry has risen to the occasion by creating a number of new ant bait products. Some of these are even targeted at individual species (for instance, carpenter ant gel bait). Another new form of baits, liquids, has emerged as an effective way to deliver insecticide to individual ants. Researchers are still unsure as to whether solid baits or liquid baits are the "best" medium to deliver ant insecticides. They both have their merits, depending on the ant species you are dealing with.

As PCOs know, there are fundamental biological and behavioral differences between ants and roaches. Here we’ll compare and contrast some basic differences between cockroach baiting and ant baiting techniques.

KNOWING YOUR OPPONENT. The first order of business in any control program is to understand the biology of the pest you are dealing with. For cockroaches this is rather simple as there are arguably no more than five to six species of any great pest importance in the United States.

On the other hand, the number of pest species of ants in the U.S. is six to eight times that of roaches. Not only are there more species, but the individual colony members can look different from each other (in many cases). Therefore, it is more important than ever to make sure that you are aware of which species you are dealing with before setting out bait.

For instance, using a sweet, gel-based carbohydrate bait may not be the best choice for a leaf-cutting ant treatment because the literature on this species tells us that their feeding preferences do not primarily include sweet substances. This bait would, however, be a perfect choice for treating ant species that feed primarily on insect honeydew. The problem becomes even more difficult to solve due to the fact that some ant species will take "sweet" substances sometimes and not at others. Scientists are still trying to understand these dietary switches and what drives them in different ant species.

Once you have determined which ant species you are dealing with, understanding where the ants are coming from is the next step to "think like an ant." In cockroach baiting programs this is also true, but the job is a bit easier because cockroach infestations are primarily an indoor pest problem, especially with the German cockroach.

Technicians have been taught to look for areas high in moisture, near exposed food sources, or most importantly, in areas that provide proper "environmental conditions," warmth and humidity for the cockroach. This translates to checking the kitchen and bathrooms of private dwellings.

Of course in commercial accounts we may have to expand our close inspection to satellite areas of the kitchen and bathrooms, food-preparation areas, food-storage areas, boiler rooms, laundry rooms, janitor stations, etc. Baiting for cockroaches as close to the harborage as possible is a good technique and one that would be favorable for ant baiting as well. Finding colonies will improve your treatment success, however, colony-locating strategies may require a bit more detective work.

Ants can be located outdoors, indoors or invading/travelling indoors from the outside. This makes finding the source of infestation a bit more difficult than with cockroaches. What are ants looking for when they enter the structure? The same thing cockroaches are looking for: food, water or shelter. Look for ant trails back to the colony. Outside, look for mounds, frass piles and dead ants. Spider webs can provide a telltale sign of nearby ant colonies or foraging trails. Also inspect around foundation walls, cracks in pavement, expansion joints, under leaf litter, mulch or rocks, surrounding vegetation and woodpiles. Ants, because of their diversity, can be almost anywhere.

Of course when scouting indoors, inspect along walls, under edges of carpet and around possible food and water sources, keeping in mind that a small bit of crumbs is a large enough food source to warrant worker ants that find the pile to recruit other colony members to the site. Remember that sanitation is important for any cockroach control program. Guess what? It’s the same case with ants.

One entomologist where I work always instructs those stricken with an indoor ant infestation to "clean up the chips, cookie crumbs and food that you drop when you eat and you won’t have any ant problem, they’ll go away." Windowsills should also be inspected because of possible entrance points as well as for the build-up of dead insects that can be scavenged by foraging ants.

IN THIS CORNER... As we all know, ants are social insects. They have a division of labor system whereby different members of the colony perform different functions.

One famous ant researcher, Edward Wilson, aptly described the ant colony as a "super organism," suggesting that if you step away from observing individual ant behaviors and take a blurred focus of the entire colony it appears to operate as a single being. Individual worker ants communicate with each other with a complex set of chemical and physical cues that may dictate the location, quality or quantity of a food source, the location of an enemy, or a general warning to be on the alert for "danger."

One commonly perpetuated fallacy of the ant colony is that their day-to-day activities are controlled by the queen. Many conditions govern the activity that occurs within a colony, environmental conditions (temperature and humidity), nutritional status, what foods or substances individual ants are fed and seasonality are just a few, however the queen or queens of most ant colonies are not responsible for controlling or "ruling" over the colony.

The queen or queens are in most ant species little more than slaves or prisoners, existing for one primary reason — to produce eggs that will eventually develop into more ants. Needless to say, the level of complexity in behavior, communication and foraging for food makes understanding ant baiting more challenging than cockroach baiting.

This social behavior and communication between ants is perhaps the single greatest behavior to exploit with ant baiting programs. The fact that worker ants share food with each other as well as the non-foraging larvae in the colony create a perfect scenario for employing ant baits containing an active that is slow enough to permit ants that feed on a bait and time to share with other members of the colony prior to succumbing to the insecticide. In this fashion, one hit on a bait can result in the death of many members of the colony. Some products even claim elimination of the entire colony due to this phenomenon.

In contrast, roach species do not have as elaborate a system of communication between individual foragers. There is little communication of food sources between individual foragers. Cockroaches, however, will eat each other and each other’s waste materials and thereby transfer of bait toxicants does occur between individuals to some degree.

Not only do ants communicate about food sources, amounts and qualities more than do cockroaches but their feeding preferences and patterns are more complex. Obviously, this is because there are many more species than there are cockroaches, but also there can be great shifts in feeding preference within species. Cockroaches are known to eat almost anything to survive. Ants are certainly more "picky" when it comes to feeding.

Baits may fail because you are baiting with the wrong food source (for instance, as mentioned earlier, sweets [carbohydrates] vs. proteins as the bait matrix can make a difference in effectiveness). Some ants are less likely to enter bait stations than others (ghost and crazy ants). Contamination of bait with foreign odors or residues, including insecticide residues, may render baits useless and stale baits or those in the presence of competitive food sources are also important to look out for and avoid.

THE KNOCKOUT PUNCH. In the context of treating with baits, what has just been discussed only scratches the surface of the differences between ants and cockroach behavior. Capitalize on the recent shift in pest prevalence from cockroaches to ants but remember to switch your thinking from roach biology to ant biology.

The two are different in many ways. Remember to "think like an ant." First and foremost, make sure you identify which ant species you are dealing with and then use the information available to you to apply baits in a manner that is as specified to the pest species as possible. In time you will become familiar with the ant species most prevalent in your part of the country or state that you live in..

There are several differences in roach and ant biology that affect bait selection and effectiveness. Here are a few:

• Cockroaches aggregate but do not form nests.

• Both small nymphs and adults forage.

• Feeding habits for most cockroach species are quite similar (scaven-
gers/omnivores).

• Food preferences change during life cycle.

• Foraging cockroaches feed individually without the constraint or control
of colony nutrient requirements.

• All female cockroaches are potentially capable of reproducing.

• Every cockroach you kill counts because all cockroaches contribute to
the reproductive success of the entire infestation aggregation.

• No seasonal changes in food preferences among foragers.

• Only a few pest species in the United States.

• No known forms of communication between individuals about food
sources.

• Following cockroaches after they feed is difficult and may or may not lead
you to harborage sites or other cockroaches.

• Primarily an indoor pest — treatment is usually indoors.

• Ants form discrete nests that harbor the queen(s) and brood.

• Only adults (workers) forage.

• Food preferences the same for individual adults/workers.

• The foraging behavior of worker ants is driven not only by the worker’s
own biological needs but by the needs of the entire colony.

• In ants, only a few (polygyny) and sometimes only one (monogyny)
females (queens) produce eggs. Other females are sterile workers.

• Killing foraging ant workers usually has little if any significant effect on the
colony.

• Ants not only change seasonally but the intrinsic feeding habits of nearly
every species is different, therefore pre-baiting (i.e., baiting with food
without insecticide) may be necessary.

• Dozens of pest species in the United States.

• Individuals within colonies communicate positions of food sources.

• The location of ant nests can sometimes be found by baiting ants with
acceptable food and seeing where the replete workers go after feeding.

• Can be treated for indoors or outdoors.