Pavement Ant (Tetramorium immigrans)

Description

The workers mostly grow up to 4 mm; however, the queen ants are bigger, reaching to lengths of 8 mm.

They have dark brown or black bodies. The appendages present, however, appear lighter than the other parts of their body. One of their prominent identifying features is the parallel lines and grooves running from their head down to the thorax.

A single pair of spines can even be seen protruding from the thorax. They have a twelve-segmented antenna, with the club divided into three distinct sections. Their petiole (narrow waist) and post-petiole are closely similar in size and shape, with the latter being slightly bigger and shinier.
The new queen ants and drones have wings twice the size of workers.

Distribution: Native to Europe, but an invasive species throughout parts of North America found in about 23 states of the U.S. and five provinces of Canada.

Habitat: Outdoors: Under pavements, sidewalks, patios, and building foundations; Indoors: Near high-humidity areas like kitchen and bathrooms since they are attracted to moisture; they also occur near heat sources during winter

Do they bite: No; being docile and non-aggressive they avoid confrontation and rarely bite; however the workers do possess a small stinger capable of penetrating human skin, causing mild discomfort

Lifespan: Workers – 5 years; Queens – 15-20 years

Predators: Spiders like black widow, jumping, and lynx; snails, snakes

Behavior and Characteristics

Diet and Foraging

The colonies comprise around ten thousand worker ants that form an integral part of the foraging trail, starting from their nests ending up to the food source. They secrete pheromones along the trail that act as an identifying mark. This helps the nest mates reach their destination and safely carry food items back to their colony.

Being omnivorous, they feed on a wide range of food like dead insects, honeydew, nectar, seeds, and fruits. They even consume human food, especially those of a greasy texture, alongside bread, nuts, meat, cheese, and ice cream.

Nest and Colony

Their nests occupy an area of 1.2-4.8 sq.m, reaching a depth of 45-90 cm. These dwelling places are marked mainly by an entrance hole, with crater-shaped sand mounds near the entrances, seen mostly during summer.

They exhibit territorial behavior leading to large battles in neighboring colonies unrelated to one another. These fights mainly commence during spring and summer when the members of each colony indulge in demarcating their domains. The result of such an extensive war is the death of thousands of ants.

Besides the workers, which form a significant part of the colonies, it even comprises a single queen. However, two or more queens could inhabit a colony in rare cases.

Life Cycle

The nuptial flights begin during spring and summer when the drones and queens leave their nests in pursuit of their mates. The pavement ant drones seek out to mate the virgin queens. After the completion of the mating ritual, the newly fertilized queen searches for a nesting location and goes on to dig a chamber.

1. Egg Stage

The eggs the queen lay hatch after around two months, developing into the first generation of worker ants. These eggs appear small and white, barely visible to the human eye.

2. Larva Stage

The legless larvae evolve when the eggs hatch and feed on the pulps of food and insects.

3. Pupal Stage

The pupae remain within a case they for around themselves until they mature into adults.

4. Adult Stage

The adults appear brown or black, and until they become old enough to forage on their own, the onus lies on the queen to look after the first generation of young ants.

Comparison with Similar Species

vs. Carpenter Ants

Carpenter ants are bigger, with a length between 9- 13 mm. In contrast, the pavement ants appear smaller measuring around 4 mm, with the queens being 8 mm long.

Carpenter ants are primarily black or a combination of black and red. The pavement ants come in shades of brown or black.

They chew through wood, causing structural damage, a trait unseen in the pavement ants.