Black garden ant (Lasius niger)

Size:

• Worker bees: 3 to 5 mm
• Queen: up to 9 mm
• Males (during swarming season): 3 to 5 mm, winged

Look:

• Glossy black or dark brown
• Clearly segmented body with a narrow "stalk" (petiole) between thorax and abdomen
• Queen larger, more massive, and with wings during mating season
• Males and queens capable of flight during swarming season

Way of life:

• Forming societies with up to 40,000 animals per colony
• Clear division of labor: queen, workers, males
• Nest building is preferred in the ground, under paving stones, in cracks in walls.
• Strong orientation towards scent trails (pheromones)

Reproduction:

• Swarming usually occurs in July or August in warm weather.
• Fertilized young queens found new colonies on their own.
• The queen's lifespan is up to 15 years.
• Males die shortly after mating.

Nest locations:

• Under paving slabs, in paving joints, flowerbeds, lawns
• On building foundations, cracks in walls, garage entrances
• Rarely directly in the house, but often in the immediate vicinity
• Colonies remain in the same location for several years.

Nutrition:

• Primarily sugary substances such as honeydew from aphids
• Also household sugar, sweets, fruit juices and baked goods
• Protein sources for larval rearing: dead insects, meat scraps
• Forms long ant trails to the food source

Behave:

• Create visible paths between the nest and the food source.
• Very persistent and organized in foraging
• No direct damage to the building structure, but hygienically problematic.
• Storage rooms, kitchens or pantries are particularly affected
• Often forms new colonies in the immediate vicinity when disturbed.

Annoyance:

• Mass occurrences especially in summer
• Ant trails through window and door gaps into interiors
• Infestation is often persistent, as the return to the food source is targeted.

Swarming flight:

• Winged ants are appearing in large numbers, entering buildings through windows.
• A visible swarm can cause unrest and irritation, psychological stress.

Disease transmission:

• Transport of microorganisms from wastewater, waste or soil

Building protection:

• Seal cracks, joints and gaps in the walls
• Check and seal window and door frames
• Seal food in an airtight container
• Do not leave food scraps or open waste containers.

Outdoor area:

• Reduce food sources such as aphid infestations
• Regularly check paving slabs and driveways.
• Remove sugar sources such as juices or sweets from the garden immediately.

Behave:

• Detect and interrupt ant trails early
• Do not use your own insecticides indoors without consulting a professional.
• Systematically observe repeated occurrences