Sydney, February 3 (ANI): A new research by Australian scientists has suggested that some animals like ants carefully measure the intensity of light during twilight to know when it's safe to come out and forage.
According to a report by ABC News, the research was carried out by biologist Dr Ajay Narendra and colleagues of the Australian National University.
Narendra said that previous research has shown that temperature acts as a trigger for some animals to go out foraging.
For example, some animals that are active at night in summer change, to being active during the morning in winter.
"This is because it helps them avoid really cold night temperatures in winter and really hot temperatures during the day in summer," said Narendra.
But many animals, including bats, only come out to feed at twilight, and little is known about what determines the timing of their activity.
In the first ever study of what triggers twilight activity in animals, Narendra and colleagues carried out a field study of the Australian bull ant.
They initially thought that sunset triggered the ants to leave the nest.
But in their experiment, they found that ants came out to forage anywhere between zero and 20 minutes after sunset.
"If it's extremely cloudy at sunset then the ants will start coming out quite early," said Narendra.But if it's very bright, with a clear sky, at sunset time, the ants will come out much later," he added.he researchers also ruled out temperature as a trigger.
Twilight temperatures at the study site ranged from 30 degree Celsius in summer to 5 degree C in winter.
"The animals are active within this broad range of temperatures which means the animals are not really looking for a temperature trigger to begin their activity," said Narendra.
The final hypothesis explored was whether the animals were using the intensity of light as a trigger for activity.
Narendra and colleagues shined a bright lamp on the nests for 45 to 60 minutes during twilight, when activity would usually occur.
The light was equivalent to that which would occur an hour and a half before sunset.
"They didn't come out until we actually turned the light off. We turned the lights off and immediately there was a big burst of activity," said Narendra.
"That shows they are, in a way, monitoring or measuring light intensity to begin activity," he added.ccording to Narendra, the reason why the ants don't go out when it's very light is to avoid bird predators. (ANI)