Pharaoh ant (Monomorium pharaonis)

Size:

• Worker bees: 1.5 to 2.5 mm
• Queen: approx. 4 mm
• Males: approx. 3 mm (winged)

Look:

• Yellowish to reddish-brown, abdomen often darker
• Very small, slim body shape
• Antennae with 12 segments, terminal segment club-shaped
• Queens and males only have wings for mating.

Way of life:

• Polygynous: Colony with multiple queens
• Workers form extremely long paths through buildings
• Nest relocation is possible in case of disturbance or poor environment.
• They live exclusively indoors in heated areas.

Reproduction:

• Year-round reproduction possible
• Swarming flights do not take place outdoors
• New colonies are formed through division (budding).
• Colonies quickly grow to several thousand animals.

Nest locations:

• Cavities in walls, baseboards, electrical distribution boxes
• Under floor coverings, in intermediate floors or wall coverings
• Near heat sources such as heating pipes or electrical appliances
• Nest locations are often difficult to find and spread across many small nests.

Nutrition:

• Prefers foods high in protein and sugar
• Carrion, meat, sausage, insects, sweets
• They also attack sterile materials, such as bandages or medications.
• The search for food takes place around the clock.

Behave:

• Extremely secretive and shy
• Only a fraction of the colony is visible.
• Spread via cable ducts, water pipes, joints and wall cracks
• Subcolonies communicate via scents (pheromones).
• Nest relocation due to pest control, heat, drought or chemicals

Hygiene risks:

• They transmit disease-causing germs such as salmonella or staphylococci.
• Can infect wounds and transmit diseases
• Particularly dangerous in hospitals, care facilities and laboratories
• Can sterile medical materials become contaminated?

Structural damage:

• Damage packaging, insulation materials and insulation

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.

Behave:

• Clean kitchens and storage rooms regularly.
• Inspection rounds of hot water pipe systems and electrical distribution boards
• If seen: report immediately to a specialist company, do not treat yourself.

Experience with carpenter ants: Cellulose insulation as a nest

In the spring of 2025, we received a request for pest control services for a carpenter ant infestation in a detached house on the edge of a forest. The affected family had already unsuccessfully contacted other pest control companies. These companies declined to treat the ant infestation over the phone, stating that working near a forest edge was not practical for them. However, we do not accept such requests without a prior inspection.

Our technician conducted a thorough on-site consultation and inspection. He quickly noticed that the affected room had a former skylight. This was closed off on the outside with a wooden frame and covered on the inside with a wooden panel. Behind this was cellulose insulation, which the carpenter ants were using as nesting material.

Since carpenter ants shred wood, the loose cellulose was ideal as nesting material. The insulation was partially eaten away and heavily soaked at the bottom. We completely removed the affected material and vacuumed up the ants. We also applied a targeted, approved insecticide.

A significant improvement was subsequently noticeable. In collaboration with a construction company, discussions were held regarding how the affected area could be structurally secured in the future to prevent such incidents from recurring. The client then initiated the necessary structural measures.