The primary habitat of Athyma perius is open forest and the surrounding secondary growth.
   There are multiple generations yearly, making it possible to find adults year round.
   As adult butterflies, the Common Sergeant looks very similar to the Common Sailor (Neptis hylas).        The major difference between the two is the white strip found on the leading edge of the forewing.
   On the Common Sergeant the white band is a single long dash with three dots.
   The Common Sailor, on the other hand, has a longer dash line and a single dot.
   Males have black wings with a series of white markings, while the female's are a blackish brown.         The ventral side of the wings are ochre yellow with the white markings as on the dorsal side but heavily margined and defined with black.
   The antennae are black and there is a spot of ochre between the eyes.
   The thorax has a band or two of bluish spots
anteriorly and posteriorly.
   The abdomen is transversely and narrowly barred with bluish white; beneath, the palpi, thorax and abdomen are pure white.
   In the female, the abdomen has a double lateral row of minute black dots.
   While females visit flowers for nectar, the males patrol the area looking for a receptive female.
   After mating, the females look for host plants on which they can lay their eggs.
   After the eggs hatch the caterpillars feed on the plant until they are ready to form their pupae.
   The estimated lifespan of the Common Sargeant is 32 days.