Effect of starvation on the feeding activity toward sugary food in the ant tapinoma nigerrimum (Nylander, 1856)

In this study, we investigated the effect of starvation on the feeding behavior of the ant Tapinoma nigerrimum. In particular, we tested the response of ants that had experienced different levels of starvation, toward sucrose solutions of increasing concentration. As expected, starved ants promptly reacted to the sugary food sources with a higher rate of acceptance as compared to satiated ones. Acceptance increased both with sugar concentration and the length of the starvation period. However, a consistent fraction of the starved ants did not feed on the solutions, suggesting that starvation had different effects on different individuals, even though they all had food ad libitum before the beginning of the tests, had comparable body sizes, and were collected from the same trail. The different acceptance of sugary solutions may be, therefore, merely because ants fed on the experimental food at different times. Interestingly, in all the experimental groups, ants appeared to satiate quickly, irrespective of the solution tested and fasting duration. This would suggest that the rate of ingestion was independent of these factors, a result partially at odds with previous studies. This study is one of the few ones dealing with the behavioral response of an ant species to a famine event.