The repeated mantra of many is to cage our animals apart. They don't do well in groups. Reptiles are solitary creatures. To be happy they need to live alone.

Recent research is proving that wrong with at least one species. Desert Night Lizards are not only live communally but as a family grouping, much like ground squirrels and primates. We see basic rearing (crocodilians) and communal denning (colubrids) in some species, but it's rare for such animals to live almost their entire lives in a familial colony.

"Very little research had been done on these lizards since the 1960s, but one paper from that time period mentioned that researchers found multiple lizards underneath single logs in the winter," Davis recalled. "So I went out into the desert to look for these fabled groups underneath Joshua tree logs, and I didn't have to find many before I started to see a pattern - the groups often contained one adult female, one adult male, and babies of several different ages."

Genetic analyses of these reptiles revealed the young lizards stayed with their mother, father and siblings for up to three years after birth. (The lizards have a life span of up to 8 to 10 years.) Some groups stuck together under the same fallen log year after year, forming what the researchers termed dynasties.

"This is remarkable, given the fact that in most species of lizards, individuals actively avoid each other," Davis said.

The article hypothesizes their family orientation is the fact that they are viviparous. I would be interested to see if this research would extend to other species. For the full article, click here.