 While the range of two hellbenders may overlap, they are noted as rarely being present in the overlapping area when the other salamander is in the area.The species is at least somewhat nocturnal, with peak activity being reported by one source as occurring around "two hours after dark" and again at dawn (although the dawn peak was recorded in the lab and could be misleading as a result).Nocturnal activity has been found to be most prevalent in early summer, perhaps coinciding with highest water depths.