Curious aliens baby lemurs are now on view at the National Zoo.

Six-year-old Molly gave birth to three red-ruffed lemurs, a critically endangered species, on April 5. The babies appear healthy and strong, the zoo says.

Keepers have covered a part of their enclosure with plastic to help the babies acclimate, but they can still be seen by visitors at the small mammal house’s mixed-species exhibit.

Red-ruffed lemurs are native to the northeastern deciduous forests of Madagascar, but deforestation, hunting, and trapping to keep them as pets have threatened their survival, according to the National Zoo.