Odorous House Ants
Description: Odorous house ant workers are brown to black and 1/16 to 1/8-inch long. The best identifying characteristic is the rancid butter smell these ants produce when they are crushed, hence their name. When alarmed, the workers scurry around with their abdomens raised in the air.
Biology: These ants swarm to mate from early May through mid-July, and also mate in the nest, forming new colonies by budding off the original colony. A colony has approximately 10,000 workers and several queens, each laying one egg a day. Developmental time (egg to adult) is 34-83 days; however, during the winter, it may take six to seven months. Workers and queens live for several years.
Habits: Odorous House Ants often nest outdoors under stones, logs, and in the nests of larger ants. They can also nest indoors in wall or floor voids, and around heat sources. These ants travel in trails and prefer sweets, although they eat almost any household food. They usually invade structures during rainy periods after honeydew on plants has washed off.
Description: The carpenter ant, Camponotus pennsylcanicus, is in the east and C. modoc in the west are the most thoroughly studied species in the U.S. They are among the largest ants found in the U.S., ranging from 1/8 to ½ inch long, the queens are slightly bigger. The workers of an established colony vary in size. They are commonly black, although species are other colors.
Biology: Ants in general have a complete life cycle consisting of egg, larva, pupa, and adult. From a single mating the female ant, now to be a “queen” in her own colony, stores all the sperm from the male in a special sac called a spermatheca, and she diligently withdraws the sperm as needed for fertilization of her eggs over her entire lifetime. She does not mate again. Carpenter Ants usually have only one queen per colony (There are exceptions to this general rule). The adult carpenter winged female or queen loses her wings soon after mating with the smaller male and selects a secluded nesting site where she raises the first brood of workers. These workers are very small but assume the care of the larvae and the queen after they mature. The queen at that point is an egg laying machine and her sole function for the rest of the life of the colony is producing eggs. Future workers are larger than those from the first brood because they receive better care. All workers are wingless. Each and every working ant is a sterile female. No male ant participates in the activities of an ant colony, other than the mating flight. Many of these larger ants have large jaws, and they can bite. This is the case with Carpenter ants, and once they have bitten and caused a little nick in the skin they then spray some formic acid from their abdomen, and this acid causes a stinging sensation.
Habits: Carpenter Ants forage at night and they love sweets. Carpenter ants find their protein mainly in the form of other insects. As they tunnel their way through the wooden structures in the home they carve off a piece of wood with their mandibles and cast it aside as refuse. When the chambers they are in get too full of this refuse, they bore a slit to the outside world and push the refuse out of the chamber (that could be called housecleaning). The Primary Nest of the Carpenter Ant is almost always out of doors–in an old tree stump or in a hole left when a branch broke off of a tree or in a fence post or other substantial mass of cellulose material. This primary colony may be as far away from the house as 500 feet. Ants from the primary colony then make their way into the home involved with leaving a pheromone scent trail for other ants to follow. If conditions in the home are favorable–that is if there is a suitable void available and enough food present, a secondary or satellite nest may be established and larvae and pupae carried from the primary nest to this secondary nest to be taken care of there until they reach the adult stage. When infested with Carpenter Ants you will hear a frantic rustling noise caused by the ants that were disturbed by knocking on the outside of the wall.
Secondary nests can occur in any void space in the house or in any galleries that the worker ants have carved out. If there is a moisture condition caused by a leaky pipe or a malfunctioning roof gutter, or any other cause of a moisture problem, it is probable that the secondary nest will be located in or next to that affected area. Larvae and pupae, but no eggs will be found in the secondary nest. The trick is to knock on the door or wall and then put your ear up to it and listen.
There is a general rule that only about 10% of the members of a colony are out foraging for food at any one time. A Carpenter Ant colony must usually be over six years old and must contain at least 2,000 individuals before it will put off a swarm of alates (winged adult male and female ants). A colony that has been in existence for a long time may have 50,000 to 100,000 individuals in it.
Description: Pharaoh Ants are very small: workers are about 1/16 inch long. They range from yellow to light brown. They can be distinguished from the thief ant because they have a three-segmented club at the end of the antenna. The Pharaoh Ant is so small that the whole colony can exist under a wet mop in a broom closet, or in the light switch box on the wall.
Biology: Pharaoh ants do not swarm. Females mate in the nest, and new colonies are formed by budding. This means part of the main colony moves to a new location. There may be hundreds of thousands of ants in a colony. The queens are about twice the size of the workers and are a dark brown color. There are multiple queens in the colony all laying eggs at the same time. A female produces 350 to 400 eggs in her lifetime. The entire life cycle is completed in 38 to 48 days at room temp. Indoors, these ants develop year round.
Habits: Most colonies will be found inside structures such as homes, Infestations may be prominent in the kitchen and in the bathroom because of the presence of water. The pharaoh ant does not bite or sting. Pharaoh Ant workers forage in the evening and at night and often come from large colo
nies of 100,000 ants or more. When a forager (worker ant) finds a good source of food it returns to the nest, leaving a pheromone trail on the surface it is traveling on. It alerts the workers in the nest, who follow this pheromone trail directly to the food source. The Pharaoh Ant loves sweets. It is omnivorous, feeding on protein and grease as well as killing and eating small insects.
Description: Pavement ants are 1/16- 1/8 inch long with a dark body and lighter colored legs. They are easily identified by the narrow, parallel grooves on their heads and thoraxes.
Habits: Pavement ants are commonly found in metropolitan areas. They nest outdoors under flat stones, under sidewalks, along curbing, under concrete slabs, etc. They invade structures in search of food and are a particular problem in areas where slab-on-grade construction is prevalent. Inside structures, they nest in walls, insulations, floors, and near heat sources during the winter. They feed on insects, meats, seeds, and sweets, but they prefer meats and greases. They are slow-moving insects and are frequently observed in areas where they are prevalent. They forage in trails as far as 30 feet from the nest. Although they are not aggressive, workers can bite and sting.
Biology: The developmental time (egg to adult) is 36 to 63 days. Indoors, swarmers emerge anytime, and they emerge outdoors in June and July.
Description: The Argentine Ant is a relatively small ant (the workers are about 2.5 mm in length and the queen is about double that size), light brown to dark brown in color and have one node on their pedicel.
Biology: The vast majority of the eggs are laid in the summer months. They are very adaptable to surroundings. In a well established colony, there can be hundreds of queens and thousands of workers. The eggs that the queen lays will hatch in about a month. The larval stage takes about a month and the pupa stage about two weeks. Thus they can mature from the egg stage to the adult stage in about two and a half months. The workers as well as the Queens can enter a colony other than their own and will be well received instead of being killed.
Habits: Workers seem to invade everything; even food in a screw top glass jar is not necessarily safe from their pillaging. Another reason for the success of an Argentine Ant colony is that the vast numbers of queens mate in their nests and thus are not exposed to the dangers of the big outside world. The male, once it is mated, leaves the nest and soon dies.
Description: Acrobat ants get their name from their habit of raising their abdomen above their head, especially when they are disturbed. When they are viewed from above, the abdomen is heart-shaped. Most species are less than 1/8th in length. Many give off a disgusting odor when disturbed.
Biology: Like all ants, the acrobat ants may produce winged, reproductive individuals (males and females) called swarmers. These sexually developed adults emerge from an established colony, usually in the fall, to disperse and start new colonies. The swarmers are harmless, but they may be the first indication of an infestation. Special treatment of swarmers beyond vacuuming or sweeping them up is not required.
Habits: Outdoors, acrobat ants nest under stones, in stumps, in rotting logs, and under woodpiles. When they invade homes, they often nest in wall voids or in foam sheathing behind siding. Homeowners often find bits of foam around the outside of the home, next to the foundation. The ants also nest in wood that has been damaged by moisture, fungus, carpenter ants or termites. Acrobat ants normally eat insects and honeydew. They protect the aphids that produce the honeydew. If acrobat ants come into a home, they seem to prefer sweets and meat.
The acrobat ant workers enter homes in several ways. Sometimes they make a trail across the ground. Door thresholds and weep holes are common entryways. Workers can also follow tree limbs or shrubs that touch the house. They have even made their trails on utility lines. The ants can enter the home through the same opening that pipes or wires go through.
Description: Thief Ants are very tiny ants, workers are never more than 1/16- inch long. Thief ants are yellow to light brown and look much like Pharaoh ants.
Biology: These ants begin swarming as winged reproductive in June; this activity continues until late fall. A colony of a few hundred to several thousand workers can be established by a single fertilized female. Development time (egg to adult) is 50 days to several months.
Habits: Thief ants are often found in very large nests that have tiny tunnels connecting to the nests of larger ants. They habitually steal food and brood from the other ants nests; thus their name. When they do nest in structures, they usually are found in wall voids and similar protected locations. Thief ants feed on live and dead insects, seeds, and honeydew. They generally prefer food with high protein content.