Observations of Snakes Associated with Active Nests of Allegheny Mound Ant (Formica exsectoides) in Northeastern Pennsylvania

Refuge availability is an important component of snake ecology and conservation, yet we have limited understanding of the extent to which snakes use the nests of other animals for refuge. Despite their ubiquity in many forests, the use of ant nests as refuge by snakes has only been reported by a few publications. Between 15 September and 14 October 2019, we set out camera traps to assess whether snakes inhabited active ant mounds and the associated habitats engineered by Formica exsectoides (Allegheny Mound Ant) in northeastern Pennsylvania. We recorded a total of 44 snake images captured at 2 ant mounds, representing 24 individual encounters and 3 snake species. Species observed entering and emerging from mounds included Diadophis punctatus (Ring-necked Snake) and Storeria occipitomaculata (Red-bellied Snake). We observed both Ring-necked Snakes and Red-bellied Snakes briefly entering and exiting nests. The latter was also observed basking outside of a nest, and we observed both species enter a nest without resurfacing. These results suggest that active ant mounds constructed by Allegheny Mound Ants represent an underappreciated resource for these small-bodied snake species.