A litter of mountain lion kittens were recently discovered in the Santa Monica Mountains in Calabasas, California, according to a National Park Service video released June 19.

The Santa Monica Mountains Recreation Area shared the news on their Twitter page on June 19. “We recently discovered a litter of 4 mountain lion kittens, all female,” the unit shared. Footage shows the kittens in their den with one of them hissing and showing her teeth to the camera.

After collecting tissue samples from each kitten, the unit found that the litter weighed between four and a half and five pounds and were four and a half weeks old. Credit: Santa Monica Mountains Recreation Area via Storyful