Are you ready to be creeped out? A new study indicates that Antarctic birds can actually recognize a human’s face.

Researchers from South Korea were monitoring breeding brown skuas when they noticed they were often attackign researchers who checked their nests, and the birds were attacking from greater distances each day, according to a Laboratory of Behavioral Ecology and Evolution at Seoul National University statement.

The researchers even attempted to change their clothes, but the birds still followed them, seeming to know that they were the nest invaders no matter what they wore.

It’s an indication that skuas have greater awareness and recognition skills than scientists had previously thought, so researchers decided to test the hypothesis further. Pairs of scientists walked both away and toward nests to see how they would react. The pairs of scientists consisted of one who had been to the bird’s nest frequently and one that hadn’t. The skuas always pestered the scientists that had been to the nest while ignoring the other scientist.

It’s been shown before that mockingbirds and crows have this ability, but these species live among humans, whereas Antarctic birds like skuas do not — suggesting this ability is innate.

“It is amazing that brown skuas, which evolved and lived in human-free habitats, recognized individual humans just after 3 or 4 visits. It seems that they have very high levels of cognitive abilities.” Dr. Won Young Lee, a Senior Researcher from Korea Polar Research Institute who led the research, said in the statement.