Humans are not the only ones who can turn irritable and aggressive between meals, according to researchers, who have observed "hangry" behaviour in fruit flies.
The study indicated that male fruit flies, which feed on decaying fruit, grew ever more combative the longer they went without food - to a point.
The quarrelsome behaviour plateaued after 24 hours, research by the University of East Anglia (UEA) and Oxford University suggested.
In nature, food abundance waxes and wanes, such that animals often find themselves in conditions of limited food availability.
Researchers scanned vials of male fruit flies, containing different amounts of food and over different periods of time, to record the number of lunges and tussles and the number of flies chasing, fencing, and occupying the food patch.
Vials were scanned either 16 or 32 times, depending on the treatment, with each scan lasting three seconds.
Senior author Dr Jen Perry, of UEA's School of Biological Sciences, said: "On the one hand, going hungry might lead to a weakened state, such that hungry individuals are less likely to win fights and so they display aggression less often.
"On the other, hungry individuals might be more motivated to fight to compete for food, leading to displays of aggression or 'hanger'.
"We found that hungry male fruit flies display more hostility toward each other.
"The hungrier they get, the more combativeness they display.
"In other words, just like humans, fruit flies get 'hangry'."
The research also suggested that increased aggression in food-deprived male fruit flies might result from a "desperado" effect, in which individuals of poor condition engage in fights even when likely to lose, because they cannot gain fitness benefits by not engaging at all.
No flies died during the experiment.
The study is published in the journal Animal Behaviour.
Australian Associated Press