Priscilla, Lois, and Arli (Arizona Black Rattlesnakes) spent their pregnancy together at a rookery from May through August, 2010. Arli moved away to a private nest shortly before giving birth, while Priscilla and Lois stayed at the rookery.
On 30 August 2010 we observed Priscilla (pregnant adult female) discouraging House (neonate / newborn) from potential exposure to a human predator. Because Priscilla was pregnant at this time, House had a different mother. To our knowledge, this is the first observation of helping – where an animal cares for another’s offspring – in a snake. Perhaps this is why some female rattlesnakes aggregate during gestation and remain together after giving birth.