The skull articulates with the vertebral column by two occipital condyles, as in mammals but unlike reptiles and fishes. Most species found in the Carolinas and Virginia reside in the mountains. The Americas have more species of salamanders than the other continents combined. Where tadpoles of anurans eat algae until metamorphosis, salamanders eat insect larva and small aquatic insects. Tadpoles have a simple horny structure in place of teeth, whereas salamander larvae possess true teeth.
Most species are nocturnal and all require moisture at all times.
Aquatic salamander food must be alive, as they hunt by motion. Collecting egg masses is the easiest method of capture, otherwise study specific species habitat requirements and lift a lot of rocks. Frog eggs tend to be small masses that string out, and toads are either singular, attached to grass leaves, or long strings of eggs with one end attached to a stick or grass stem. Most terrestrial salamanders are inactive during cold weather, and some hibernate. Those salamanders living in pools, streams, or seeps, depend on the temperature of the water to regulate their activity.