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A band of wild chimpanzees have been caught on camera slipping into fields under the cover of darkness to steal ears of maize. 

The apes, which included females and infants, were then seen escaping back into the Ugandan forest clutching armfuls of the crop. 

Over a 20-day period the primates were filmed raiding the nearby maize fields a total of 14 times. 

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Over 20 days, researchers observed parties of around eight chimpanzees climbing across a branch and lowering themselves into maize fields near the Kibale Forest National Park, Uganda, where they would spend up to two hours foraging. The group carried out this act a total of 14 times

Primatologists believe the behaviour is an adaptation the chimpanzees have learnt as their normal habitat in Kibale Forest National Park, is being destroyed by commercial logging.

The animals predominantly performed the raids on moonless nights because they were less likely to be spotted by the local farmers who guard their crops as they reach maturity, said the researchers.

Dr Sabrina Krief, from the National Museum of Natural History in France, explained: 'To our knowledge, this is the first report of long, repeated and group night activities by a great ape species outside of moonlit nights.

'The nightlife of chimpanzees has been neglected and we have probably missed some interesting activities as night-time lasts around half of each 24 hours in the equatorial regions.'

The researchers, whose findings are published in the journal Plos One, set up cameras on the edge of an area of forest where it bordered a maize field.

Over 20 days, the research team observed parties of around eight chimpanzees climbing across a branch and lowering themselves into the maize field where they would spend up to two hours foraging. 

Footage then shows them stealthily creeping out of the fields and back into the direction of the national park.  

The chimps also carried out their raids throughout the day, but the researchers spotted the animals were noticeably more anxious during these light hours.

Although the raids occurred at different times over the 20-day period, the chimpanzees predominantly carried out the robberies on moonless nights (pictured) because they were less likely to be spotted by the local farmers who guard their crops as they reach maturity

In a number of the recordings, the animals were seen scanning the distance, scratching themselves and regularly defecating, often diarrhoea, which the study claimed is a common sign of nervousness.

A number of the animals also appeared to be standing guard during the recordings, too, in which they assumed a quadrupedal posture for more than five seconds without moving. 

Dr Krief added: Even though the chimpanzees' home range has been seriously damaged and disturbed by both logging activities and significant human demographic pressure, chimpanzees have shown great behavioural flexibility including unexpected nocturnal behaviour, in order to take advantage of the proximity of domestic nutritive food.' 

Cheeky Chimpanzees filmed making night-time raids on farms

Experts believe the behaviour is an adaptation the chimpanzees have learnt as their habitat in the Kibale Forest National Park (pictured) is being destroyed as a result of commercial logging and degraded agricultural lands