A new study found that fruit flies have a sense of time and can tell the time of the day. The findings of the study provided evidence that even the small animals, which have small brains, are smarter than previously thought.
Earlier studies have found that mice and honeybees can associate reward with a particular time of the day. Researchers at Rudolf Virchow Center in Germany set out to determine whether this behavior also applies on smaller species such as the fruit flies.
The team exposed the hungry fruit flies to two different scents with sugar for two days. They divided the flies to a morning group and afternoon group. On the third day, they tested which scent the flies would choose. The experiment showed that the flies exposed in the morning scent chose the sugar in the morning, while the flies scheduled in the afternoon preferred sugar in the afternoon.
The findings suggest that the fruit flies know the difference of morning and afternoon, and that they can tell the time of the day.
"If even the fly, with its miniature brain, has the sense of time, most animals may have it," Martin Heisenberg of Rudolf Virchow Center in Germany, said in a press release.
So how can the fruit flies tell the time? The researchers believe that the small animals rely on the light-dark cycle. They observed that when they kept the lights on, the fruit flies weren't able to differ morning from afternoon.
The researchers plan to continue their study to determine why fruit flies are drawn to certain odors, regardless of the time of the day.
"Given the formidable collection of genetic tools for studying the fly brain, this can now be achieved," Heisenberg said.
The study was published in the May 28 issue of Current Biology.