Caterpillar Nectar May Control Ants Behavior Humans are not the only animals on the planet that enjoy taking a load off with a beer, or a cigarette, or whatever you may enjoy. There are plenty of animals in nature that cannot seem to get enough of some type of substance. There have been plenty of studies that demonstrate how some addicted animals behave when they don't get their fix, and they do not take it well. One creature that enjoys a mind-altering substance is a particular species of Japanese ant referred to as Pristomyrmex punctatus. This ant will steal nectar from neighboring caterpillars, which causes the ant to behave strangely. According to a study published in Current Biology the punctatus ant will demonstrate protective behaviors towards the caterpillars after consuming the nectar. This nectar is excreted by the caterpillars, which has led many researchers to theorize that the caterpillar-nectar is an adaptation that helps the caterpillars survive. In any case, the nectar seems to completely "brainwash" the Japanese ants after consumption. Researchers from Kobe University in Japan have found that consuming the caterpillar-nectar makes ants more aggressive and territorial. The researchers also noted that the ants had lower levels of dopamine in their bodies. Dopamine is a neurotransmitter in animals that causes feelings of pleasure. So apparently, these particular Japanese ants are addicted to a drug that produces feelings of displeasure, and they are forced to protect caterpillars during their entire lives. These ants have to be the unhappiest ants on earth. As a result of these findings many scientists are rethinking the nature of the relationship between Japanese ants and the caterpillars referred to as Narathura japonica. Traditionally, the relationship between the ants and the caterpillars was considered "mutualistic", but now the evidence is suggesting that the relationship is more "parasitic". Researchers are still unsure if it is only the sugar in the caterpillar-nectar that attracts ants, or if there is some other factor that makes the ants crave more and more caterpillar-nectar. Why do you think that Japanese ants return for more nectar if consuming the nectar produces unpleasant sensations?