[5] N. serricomis is an active predator and has a varied diet consisting of many smaller invertebrates such as midges, caddisflies, black flies, mayflies, ostracods, and small crustaceans.

After the adults emerge from the chambers, they need up to an hour to dry before they can fly away and find mates, although they are relatively poor fliers, so they do not move very far from their pupation site.

The adults only live for about a week and in this time, they need to mate, and the female needs to find a site to deposit her eggs, known as an oviposition.

Year-round presence of N. serricomis larvae in streams results in generally stable respiratory responses to temperature.

Physiologically, N. serricomis larvae are adapted to maintain a constant oxygen consumption regardless of temperature, season or stage of larval development.

[9] This interspecific competition affects the N. serricornis very little due to their generalized diet but when the two do interact Corydalus cornutus dominates.