Crawling – Biting
This type of ant has two distinct sizes of workers. The larger ones, called major workers, typically range in size from 0.125 inch to 0.25 inch in length, depending on the species. The major worker is easily identified by the extremely large size of its head in comparison to its body. The head of the minor worker is in proportion to its body.
Most are reddish brown in colour.
Big-headed ants, like all ants, establish well-defined trails between the nest, food and water sources. They feed on a wide variety of foods including dead insects, plant materials, and garbage. The workers are partial to the sweet honeydew produced by aphids, scales, and mealybugs found feeding on many trees and plants. Fruit trees, roses and many shrubs serve as hosts for aphids and may contribute to ant infestations in homes and other buildings. One species, Pheidole megacephala, establishes large “super colonies” consisting of dozens, if not hundreds of sub-colonies connected by interlocking trails. These super colonies have been found to extend over large portions of a city block, making control efforts on a single property quite difficult to achieve. They have been known to construct mud tubes that can resemble those made by subterranean termites, although this behaviour is not common.
Big-headed ants are soil-nesting ants, most commonly found nesting outdoors beneath stones, logs and landscape timbers. These ants also are commonly found inside the soil of potted plants and many inside infestations may be traced to planters. In addition, big-headed ants may be found nesting beneath slab foundations and entering through cracks in the slab. On occasion, these ants will nest inside rotted wood or will excavate old termite-damaged wood to make a nest.
Tips for Control
Because big-headed ants are soil nesters, their colonies are often easy to see due to the piles of displaced soil formed as they excavate tunnels in the ground. Most colonies are relatively small and easy to treat, but treating infestations involving multiple colonies requires experience.
General tips for limiting ant infestations include:
Eliminating piles of lumber, bricks or other debris that could serve as a nesting site for ants.
Keeping landscape mulch less than 2 inches thick and at least 12 inches away from foundations.
Ensuring the sprinkler system does not spray directly onto the foundation.
Sealing as many cracks in the building’s exterior as possible.
Keeping tree and shrub branches trimmed to prevent touching the building.
Considering re-landscaping to avoid using plants that are prone to aphids and similar insects. At the very least, treat such plants for aphids regularly. A tree/shrub company can be helpful with this task.