Insect Species – Page 35 – Nature Blog Network

Ants are abundant throughout Canada, adapting to make their homes in urban and rural settings alike. While ants play important roles in the ecosystem, certain species have evolved to live in close contact with humans, sharing our dwellings and competing for our food. These ants can become pesky home invaders. Of the over 12,000 ant species worldwide, there are 7 types that most commonly infiltrate Canadian households. Read on to learn about the identifying features, nesting habits, and control methods for carpenter ants, odorous house ants, Argentine ants, pharaoh ants, pavement ants, thief ants, and black ants - the ants you're most likely to encounter inside your home or on your property. Ant Type Appearance Nesting Behavior Carpenter Ants Large, 5-15 mm long. Black or reddish-black. Distinct hourglass shape. Nest in wood, trees, logs, lumber. Prefer moist damaged wood. Build galleries and chambers. Odorous House Ants Small, 2.4-3.2 mm long. Black or dark brown. Coconut odor when crushed. Nest anywhere - soil, mulch, walls, under floors. Multiple queens per nest. Argentine Ants Light to dark brown, 2-3 mm long. Segmented petiole with raised node. Nest in soil, under objects. Massive cooperative colonies. Prefer warm areas. Pharaoh Ants Tiny yellow or yellowish ants, 1.5-2 mm long. Narrowed wasp waist. Nest indoors in walls, floors, appliances. Interconnected nests. No centralized colony. Pavement Ants Black to dark brown, 2.5-5 mm long. Nest under pavement, soil, sand, gravel. Indoors in walls, under carpet. Thief Ants Tiny yellowish-brown to black, 1-2 mm long. Decentralized nests, steal nest sites. Found indoors and outdoors. Black Ants Shiny black to dark brown, queens 5-10 mm long. Outdoors in soil, under objects. Occasionally nest indoors. 1. Carpenter Ants Carpenter ants get their name because they build their nests in wood. They tunnel into wood to build galleries and chambers. The most common carpenter ant species found in Canada is the black carpenter ant (Camponotus pennsylvanicus). Carpenter ants are large, ranging from 5-15 mm in length. They are black or reddish-black with a thorax that is evenly rounded. The worker ants have a distinct constriction between the thorax and abdomen, giving them an hourglass shape. Carpenter ants nest both indoors and outdoors in moist, rotten, or decaying wood. They can be found nesting in tree stumps, logs, lumber, telephone poles, and wooden structures. Indoors, they nest in wet, damaged wood in roofs, walls, flooring, door frames, and window sills. Carpenter ants don't actually eat wood. They excavate it to make their nests. They make smooth, clean galleries that run with the grain of the wood. Their nests consist of galleries and chambers connected by small holes. Carpenter ants need a continual moisture source to survive, so their nests are often found in moisture-damaged wood. Carpenter ants become a nuisance when they move indoors. It indicates there is a moisture issue that needs to be addressed. They don't pose a structural threat like termites. But they can damage wood over time. Carpenter ants feed on sources of protein and sugar. They have a varied diet that includes insects, honeydew from aphids, plant and tree sap, fruits, meats, grease, and sweets. Foraging worker ants leave trails along the edges of structures as they search for food. Seeing these ants indoors often means they are nesting inside. Recommended treatment includes finding and treating nests directly, sealing entry points, and pesticide sprays. 2. Odorous House Ants Odorous house ants (Tapinoma sessile) are one of the most common ant species found in urban areas across Canada. They are small ants measuring only 2.4-3.2 mm in length. Odorous house ants are black or dark brown and have a distinctive rotten coconut odor when crushed. The antennae have 12 segments with no club. The node of the pedicel is hidden by the abdomen. Odorous house ants nest almost anywhere, including outdoors in soil, mulch, under stones, in logs, or at the base of trees. Indoors they nest in wall voids, under floors, around heat sources, and in insulation. Nests contain multiple queens and can reach populations in the hundreds of thousands. These ants have a varied diet and opportunistically feed on sweets, proteins, grease, dead insects, and honeydew from aphids. They follow scent trails along edges and structures when foraging. Odorous house ants get their name from the coconut-like smell they emit when disturbed. They release this odor as an alarm pheromone to alert the colony when threatened. Though they don't sting, they can bite with their mandibles. Odorous house ants are a nuisance pest, building nests and foraging indoors. They can enter structures through cracks in foundations, walls, doors, windows, and openings for wires or pipes. Recommended treatment includes finding and eliminating nests, sealing entry points, baits, and insecticide sprays. 3. Argentine Ants The Argentine ant (Linepithema humile) is common in urban areas of southern Canada and along the Pacific coast. They were introduced from South America. Argentine ants are light to dark brown and measure only 2-3 mm in length. They have a segmented petiole with a raised node, and antennae with 12 segments. Argentine ants form massive colonies containing hundreds of queens. This results in huge populations of ants that act as a cooperative colony, rather than as smaller individual nests. Argentine ants build nests in soil, under objects on the ground, and inside protected voids. They do not tolerate cold temperatures well. In cooler climates, they will nest in protected areas indoors, such as wall voids, under floors, and around heat sources. Argentine ants have a varied diet and consume sweets, proteins, fats, and insect honeydew. They follow scent trails along the edges of structures to find food sources. Argentine ants are a nuisance pest, invading homes in search of food and water. They can enter through the tiniest cracks and crevices in foundations. Argentines do not have a painful sting but can bite. Recommended treatment includes sealing up entry points, removing outdoor nests, bait stations, and insecticide sprays. Eliminating Argentine ants is difficult due to their massive cooperative colony structure. Treatment is focused on controlling populations and keeping them out of structures. 4. Pharaoh Ants Pharaoh ants (Monomorium pharaonis) are tiny yellow or yellow-brown ants that measure only 1.5-2 mm long. They have a narrowed "wasp waist" between the thorax and abdomen. Antennae are 12-segmented. Pharaoh ants nest indoors in warm environments in hospitals, food-handling facilities, and homes. They prefer temperatures of 80-86°F and do not tolerate cold. Pharaoh ants build small nests in wall voids, crawl spaces, behind baseboards, under floors, in equipment, and near heat sources. Colonies contain multiple queens and workers. There is no centralized main nest. Nests are interconnected by scent trails the ants follow when foraging. Pharaoh ants eat a wide variety of foods including sweets, proteins, grease, dead insects, and honeydew from insects. Pharaoh ants are difficult to control because colonies contain many queens and interconnected nest sites. They can easily move nests if disturbed. Control methods include finding and treating nests directly, applying insecticidal baits, sealing cracks and crevices, and maintaining a clean environment with minimal food sources available to the ants. Pharaoh ants do not sting but they can contaminate food in pantries and commercial kitchens. They spread disease organisms through their nesting and foraging behaviors. 5. Pavement Ants Pavement ants (Tetramorium caespitum) are common ants found in urban areas across Canada. They are black to dark brown and measure 2.5-5 mm in length. Pavement ants get their name from typically nesting under pavement like sidewalks, driveways, road edges, stones, and rubble. They build nests with chambers and galleries in soil, sand, gravel, or under debris on the ground. Pavement ants will also nest indoors in wall voids, under floors or carpet, and around heat sources. Colonies contain hundreds to thousands of workers with multiple queens. Pavement ants forage day and night for food including sweets, meats, grease, vegetables, insects, and honeydew from aphids. They follow scent trails along structural edges while searching for food. Pavement ants can enter homes through cracks in foundations and under doors. They are difficult to control since colonies contain multiple interconnected nest sites both indoors and outdoors. Treatment involves locating and directly treating nests, sealing up entry points, removing food sources, and using insecticidal sprays and baits. Pavement ants can bite but do not pose a health threat. They are primarily a nuisance pest when foraging and nesting inside homes. 6. Thief Ants Thief ants (Solenopsis molesta) are tiny ants that measure only 1-2 mm long. They are yellowish-brown to black. Thief ants get their name because they do not build centralized nests. Instead, they “thieve” food and nesting sites from other insects. They have multiple interconnected satellite nests without a main colony center. Thief ants nest indoors and outdoors in a wide variety of locations. They favor moist environments and can nest in soil, under objects, in wood, in insulation, behind walls, and under floors. Colonies contain hundreds to thousands of workers but only one queen. Thief ants have opportunistic feeding habits. They eat proteins, fats, sugar, insects, honeydew, dead animals, fruit, seeds, and fungi. They do not follow scent trails like other ants. Instead, they wander randomly in search of food. Thief ants can invade homes and become an indoor nuisance pest. They do not pose a health threat, as thief ants do not sting or transmit disease. But they can contaminate foods by foraging in kitchen pantries. Control methods include sealing entry points, removing food sources, applying insecticidal baits, and locating and directly treating nests. Their scattered, decentralized nesting behavior makes thief ants difficult to fully eradicate. 7. Black Ants Black ants (Lasius niger) are also called Cornfield ants. They are ubiquitous in Canada, found coast-to-coast in a variety of environments. Black ants measure 2.5-5 mm long and are shiny black to dark brown. Queens are larger at 5-10 mm long. Black ants build nests outdoors in soil, rotting logs, under stones, and at the base of trees. They occasionally nest indoors in wall voids or under floors if there is a moisture issue. Black ant colonies can contain thousands of ants. New colonies are formed when winged reproductive females and males swarm in mating flights. After landing, the male dies and the now-fertilized queen loses her wings. She excavates a small chamber to start a new nest and begin laying eggs. Black ants will forage both day and night for sugary foods, grease, meats, seeds, insects, and honeydew produced by aphids. They follow scent trails very efficiently while foraging. Black ants rarely sting but can spray formic acid for defense. They are a nuisance pest when they forage inside homes. Preventative treatment includes sealing cracks, eliminating moisture issues, removing food sources, and using desiccant dusts at entry points. Insecticidal sprays and baits can control foraging workers. Locating and directly treating the main outdoor nests provides the best control of populations.