Black garden ants (Lasius niger) are a common sight in gardens and homes across Europe, Asia, and North America. Understanding their diet is important for comprehending their behavior and roles within local ecosystems. These ants are opportunistic omnivores, consuming a wide range of organic materials to sustain their colonies. Their dietary preferences influence their activities and where they choose to establish their nests.
Main Dietary Components
Black garden ants have a strong preference for sugary substances, which provide them with essential energy. A primary natural source is honeydew, a sweet liquid secreted by aphids and other sap-feeding insects. Worker ants often “farm” aphids, protecting them from predators in exchange for this sugary secretion. Beyond honeydew, they also consume nectar from flowers, fruit juices, and human foods like spilled sugary drinks or ripe fruit found indoors.
Proteins are an important component of the black garden ant diet, especially for the queen and developing larvae. They acquire protein by preying on small insects like flies, caterpillars, and other soft-bodied arthropods. These ants also scavenge for dead insects and may consume small pieces of meat or pet food. This protein intake is essential for the growth and development of new ants.
Fats and oils also contribute to their nutritional needs, found in various organic matter and human food scraps. This combination of sugars, proteins, and fats allows Lasius niger colonies to thrive in different environments.
How Black Garden Ants Find Food
Worker ants locate and gather food for the entire colony. They venture out from the nest to forage. When a worker ant discovers food, it lays down a chemical trail, known as a pheromone trail, to guide other ants. This creates the visible “ant lines” often seen leading to a food source, allowing for efficient recruitment.
Once food, particularly liquid or semi-liquid, is collected, it is transported back to the nest. Inside the colony, black garden ants engage in trophallaxis. This involves the mouth-to-mouth transfer of liquid food from foraging workers to other nest mates, including the queen and larvae. This communal sharing ensures all colony members, even those who do not forage, receive nourishment.
Shifting Dietary Needs
A black garden ant colony’s dietary emphasis can change based on its internal needs and external conditions. During colony growth, there is an increased demand for protein to support developing larvae. Sugars, however, remain a constant energy source for adult workers, fueling their foraging and colony maintenance activities.
Seasonal availability also influences their diet. Honeydew, for example, is more abundant during warmer months when aphid populations are high. In colder periods, ants might rely more on stored food reserves or shift to different protein sources. Their diet also varies between outdoor and indoor environments, reflecting their adaptability. Outdoors, they primarily consume honeydew and insects, while indoors, they often scavenge human food crumbs, spills, and pet food.