Camera traps in Uganda have captured the first known recordings of “frequent and risky” night raids for food on human farmland, according to a BBC News report.

The footage was captured by researchers from the Museum of Natural History in Paris and the Uganda Wildlife Authority and shows how chimps respond to pressures placed on their habitat by humans.

Researchers studied Kibale National Park in Uganda by putting up camera traps on the outskirts near farms and tea estates. They believe that human encroachment on chimp habitats is prompting the chimps to respond with foraging expeditions on human land, but were still taken aback at the brazenness of the raids.

Researchers observed groups of about eight chimps, which included females holding infants, going into maize fields and searching for food. Despite venturing into human territory, they did not show many signs of being nervous, which they usually indicate by looking around or scratching themselves.

Since habitat loss is a greater threat to chimps than predators, they will go to great lengths to reclaim land even though it means potentially being attacked or killed by people defending crops. Scientists believe that this is why they prefer to raid at night — it helps them avoid detection.

Although the behavior shows the chimps can adapt to difficult circumstances, Dr. Catherine Hobaiter, a chimp expert at the University of St. Andrews in Scotland, said in the BBC report that it was also worrying because it speaks to just how much habitat chimps have lost, and crop raids aren’t a long-term solution as humans adapt themselves to ward off the raids.