Why do ants favour feeding on sugary products?
HARIHARAN N .
Coimbatore, Tamil Nadu
In an ant colony, food is gathered by the foragers who constitute about 10 per cent of the colony members. The worker ants usually transfer the food or other fluids among the colony members through mouth-to-mouth (trophallaxis). Ants feed on a variety of food items, not just limiting themselves to the sugary products.
They can feed on pieces of solid food, seeds or grains, nectar, sugar, candy, honeydew, dead insects, etc. However, their food preferences vary with the nutritional demands of the colony members.
For example, the foragers might collect the protein-rich food for the queen, when she is actively laying the eggs. Similarly, protein-rich foods are preferred when the colony has a high larval population.
When the colony has no larvae, the foragers preferably gather the sugar-rich foods, because adult colonies consuming protein-rich food have extremely high mortality due to protein toxicity.
Even if they find a food which is rich in protein but poor in sugars, they extract the sugars and eject the protein as a waste. Hence, it is quite normal to see the foragers attracted towards sugary products (carbohydrates), unless there is a demand for protein by the egg-laying queen or the larvae.
DR. R. SRINIVASAN
Entomologist and Head of Entomology Group
AVRDC-The World Vegetable Center
Tainan, Taiwan
