Ants are highly resourceful and opportunistic omnivores. Fruit represents an extremely valuable, concentrated source of energy that is readily accessible. The primary attraction is its high energy density and moisture content, which ants can detect from a considerable distance. This dietary preference explains why ants congregate around certain types of produce both in the garden and within the home.
Specific Fruits That Attract Ants
Ants prefer fruits that are overripe, damaged, or decaying, as the breakdown of cell walls makes the inner sugars and juices easier to access. Soft berries, such as strawberries and raspberries, are attractive targets due to their delicate skins and high sugar content. These fruits are easily breached by foraging workers, allowing them to rapidly collect the liquid interior. Accessibility is a major factor; any fruit with broken skin is more likely to be swarmed than intact produce.
Tropical fruits, including bananas and mangoes, draw significant attention, especially once they have fallen or developed bruises that expose the flesh. Orchard fruits like apples and pears, when lying on the ground, become prime targets as they ferment and release aromatic compounds. Ants like the black garden ant (Lasius niger) forage heavily on fallen or damaged fruit during the late summer when these resources are abundant outdoors.
Nutritional Reasons for Fruit Consumption
The primary driver for ants’ attraction to fruit is the presence of simple carbohydrates, specifically monosaccharides like fructose and glucose. These sugars are easily digested and provide a quick burst of energy to worker ants, fueling their search for food and their journey back to the nest. This rapid energy source is necessary for the colony’s daily activities, including building, defense, and caring for the young.
Fruit offers a substantial source of water, which is important for ant survival in dry environments or during hot weather. The high moisture content helps regulate the colony’s internal humidity and provides hydration for the developing larvae. Worker ants consume the sugary fruit juice and store it in their abdomens, carrying it back to the nest to be shared with the queen and other colony members through trophallaxis.
Ants and Seed Dispersal
Beyond consuming the fruit’s flesh, ants engage in a specialized ecological relationship with certain plants known as myrmecochory, or seed dispersal by ants. Many plants have evolved a fatty, protein-rich appendage on their seeds called an elaiosome. This structure is the specific reward that attracts the ants, not the seed itself.
Ants carry the entire seed, known as a diaspore, back to their nest, where the elaiosome is removed and consumed or fed to the larvae. The viable seed is then typically discarded in a nutrient-rich refuse pile or midden, effectively planting it in a protective, fertile environment. This behavior benefits the plant by moving the seed away from the competition of the parent plant and providing a favorable germination site.
Methods for Protecting Fruit
Protecting ripening fruit from ants relies on non-chemical deterrents and physical exclusion. For fruit trees, a sticky barrier applied around the trunk is an effective method to prevent ants from climbing up to the fruit. Commercial products or substances like petroleum jelly can be applied to a band of tape wrapped around the trunk, creating a moat that the ants cannot cross.
Maintaining a clean environment is important, which includes immediately removing fallen or overripe fruit from the ground beneath trees and bushes. In the kitchen, storing ripe fruit in sealed containers or the refrigerator cuts off the food source that initially attracts scout ants. Natural deterrents like diatomaceous earth around the base of plants can be used, as the sharp particles damage the ants’ exoskeletons.