Ants belong to the order Hymenoptera, which are social insects. All ants live in groups called colonies and depend on each other for the survival of the group. There are basically three castes of ants in every colony: workers (some colonies have soldiers), female reproductives, and male reproductives. The reproductives will emerge at a specific time of the year (usually spring, though this varies by species) to mate and begin new colonies.

The reproductive period is called swarming since the male and female reproductives all leave the nest at the same time to fly off and find a mate from another colony. After mating, the male dies, and the newly inseminated female or queen selects a nest site. Once a suitable site has been located, the new queen will break off her wings, excavate the site to her satisfaction, and begin laying eggs. The queen raises this first brood through the larval stage, but once they pupate and emerge as adults, these workers take over the functions of foraging for food, further nest excavation, and brood rearing. The queen's only responsibility from this point on is to lay eggs. Once the colony is well established, the queen will begin to produce some reproductives as well as workers.

Of the ants which infest schools and childcare centers in Indiana, there are four that tend to be either more prevalent, or are of greater concern due to their potential impact. These are Carpenter Ant - specifically the Black Carpenter Ant (Camponotus pennsylvanicus), the Pavement Ant (Tetramorium caespitum), the Pharoah Ant (Monomorium pharaonis), and the Citronella Ant.

Ants are not pests in the sense that many other facility-infesting insects are pests. Although ants can sting or bite, the varieties encountered in Indiana are not a stinging or biting threats. Likewise, unlike many other insect pests, ants are not major vectors of disease, and in Indiana, do not constitute a threat to human health. By far, the majority of ants that show up in school only constitute a temporary annoyance or distraction. The decision to elevate the ant to pest status needs to be undertaken by the administration, in consultation with the IPM Coordinator and should be on a case-by-case basis determined by the ant species involved, and according to whether the colony is nesting in the school or simply entering the building to forage. Action should be taken if there are persons who are frightened of ants, or if the ants constitute a genuine structural nuisance. If children are distracted by ant activities, think of it as an opportunity for a spontaneous learning experience. After some discussion about ants, most children will be ready to move on to another subject. If the ants are just foraging and aren't bothering anyone, there is not a problem and they will leave soon enough if there is little food available.

The Carpenter Ant is one species which may potentially cause damage. The Black Carpenter Ant has workers which range in size from one-quarter to one-half inch in size. In addition to being large and black, their abdomen is frequently covered in gray or yellowish hairs. Normally these ants are of great benefit to their local environment because they kill and eat thousands of insects that are capable of forest defoliation. If, however, a colony of carpenter ants nests within a building, there will be structural damage, and if left alone, this damage will become severe. Carpenter ants nest in wood and are especially attracted to moist wood (or foam insulation) which is easily excavated. They cause damage by gouging out galleries for their nest in the moist wood. These galleries have smooth sides, because the ants remove all wood shavings and dust and discard it in piles away from the nest. Carpenter ants may forage within a school or childcare center for food such as sweets, meats, fruit juice, or kitchen refuse, without actually nesting in the building. However, nests close to a building, such as in trees, stumps, telephone poles, wood piles, etc. also pose potential threats to the structure, because as carpenter ant colonies grow, they establish satellite colonies. Thus, when seen indoors, it is important to determine if the ants are really carpenter ants, and if so, from where they are coming. Watch for indicators that there may be a nest in the building, such as piles of what looks like sawdust, or slit-like holes in woodwork, such as door casings. Also, listen for rustling sounds in walls or woodwork.

Pavement ants may become nuisance pests because occasionally they will also establish colonies indoors. While normally nesting outside, these ants are not averse to nesting under floors or in walls. These ants are about one-eight inch long and range in color from light reddish brown to almost black. Pavement ants can be identified by their shiny abdomens, though the heads and thorax appear dull due to small parallel furrows along the front, top, and sides. These ants normally enter a building searching for greasy and sweet foods. When nesting inside, they will leave little piles of junk, which they clean out of their nests, around the nest site. Watch for these dumping piles to determine if there is a nest inside the building.

The Pharaoh ant is a native of Egypt and North Africa and cannot survive outside during cold weather. For this reason, these ants become a nuisance because they must nest inside to survive. At about one-sixteenth inch long, these tiny ants are dull yellowish to light orange in color. Unlike most ants, Pharaoh ants maintain multiple queens per colony, and they do not swarm. The reproductives do not have wings, so rather than flying off to mate with ants from other colonies, new queens mate with their brothers or cousins. When a colony gets too large, some queens and workers will walk away to start another nest. One colony will spawn many others as emigrants move through walls and ducts to other parts of the school. They are especially attracted to sweet and starchy foods, but will eat food of all types. They are also attracted to liquids, and floating ants in cups, glasses, or the basins under plants may be the first signs that there are Pharaoh ants in the school or childcare center.

Citronella ants are about one-eighth inch and brown. They do not live inside, but will frequently forage inside in search of sugary food. They are less of a pest than a distraction, and the best method of keeping them out of buildings is sanitation. If there is sugar available, there will be Citronella ants in the school.

The first step to control ants is sanitation. Ants usually enter buildings in search of food and water. Do not store food in desks or lockers. Clean up all spilled food and liquids immediately, and inform custodial staff when there is an activity involving food in a classroom so that special attention may be focused on the sanitation of that room soon after the activity is over. Repair leaky faucets and pipes, and empty water containers that stand overnight. Keep all stored food in sealed containers. Caulk cracks and small openings where ants may enter (windows and wall penetrations for utilities). If ants are entering from outside, try to determine where they are entering and seal the opening. Occasionally rearrange supplies to expose possible nests.

Obviously, different species of ants will warrant different responses. When ants are in the building, first identify what species of ant it is, and try to determine why it is there. Next, determine if the situation needs a response. Is a control measure necessary? Lastly, if it is determined that a response is necessary, decide what form the response measure should take. These questions should be answered in consultation with the IPM Coordinator. If destruction of the nest is necessary, a bait may be used. In the case of Carpenters ants, the IPM Coordinator will determine and arrange for a control measure.

There are some specific actions which may be taken specifically to prevent infestation by Carpenter ants. Carpenter ants will be attracted to moisture in the building, so try to keep the facility as dry as possible. Fix leaky spots in the roof, walls, and foundation where moisture may penetrate. Regrade areas where water drains toward the building. Make sure flashing around vents and pipes is properly attached. Ventilate areas where moisture accumulates. In addition, get rid of potential nesting sites around the building, such as wood piles or stumps. Trim tree branches away from the building to prevent a possible bridge from wood to structure.

Ants nesting within the school, especially Carpenter ants, require a response decision. Foraging ants may need to be dealt with if their numbers are excessive, or if they are overly distracting. By and large, however, if it can be determined that ants are not Carpenter ants, and they are not entering the building from outside, these ants constitute a potential annoyance or class lesson, but are not really worrisome pests.

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