The most common food items are ants, caterpillars, and beetle larvae. In the early fall, individuals will retreat to underground burrows where they maintain a fossorial existence. Sometimes their burrows extend more than a meter below the surface. Plethodon neomexicanus , as with the rest of tribe Plethodontini, lacks an aquatic larval stage and development proceeds directly from the egg to juvenile stages. Sexual maturity is attained after two to three years in males and three years in females.
Females mate every other summer and oviposit sometime before the following spring.
It is inferred from laboratory data that females brood clusters of five to twelve eggs through hatching. Unfortunately, courtship has not been described and nests have not been found. This species is not one to add to your collection as the U.S. Fish and Wildlife Service list it as a Candidate species. The State of New Mexico also lists it as Threatened. Data on long-term population trends is not available nor is there data on the affects of logging or other types of human disturbance.