There are four castes of these termites, the nymphs (sizes varies from 4 to 6 mm, color is white or creamy), the larvae (traslucent and smaller than the nymphs), the soldiers (whitish, with prominent brown heads and strong mandibles, length of about 8 mm) and the breeding adults.
Kalotermes flavicollis has no special caste of adult workers since all the tasks in the colony are performed by nymphs.

The adults reach 8–10 millimetres (0.31–0.39 in) of length, with a wingspan of about 20 millimetres (0.79 in).
The basic coloration of their body is pale yellow or dark brown.
The pronotum is yellow-orange (hence the Latin name flavicollis, meaning 'yellow-necked'), while antennae and distal parts of legs are pale yellow.
The male (the king) and the female (the queen) have a more chitinous body, as well two pairs of membranous wings, long, narrow and slightly smoky, essential in the nuptial flight.
The wings are held horizontally, overlapping the abdomen when the insect is at rest, so that just one wing is visible.
The females are on average a little larger than males.
There are four castes of these termites, the nymphs (sizes varies from 4 to 6 mm, color is white or creamy), the larvae (traslucent and smaller than the nymphs), the soldiers (whitish, with prominent brown heads and strong mandibles, length of about 8 mm) and the breeding adults. Kalotermes flavicollis has no special caste of adult workers since all the tasks in the colony are performed by nymphs.
The adults reach 8–10 millimetres (0.31–0.39 in) of length, with a wingspan of about 20 millimetres (0.79 in). The basic coloration of their body is pale yellow or dark brown. The pronotum is yellow-orange (hence the Latin name flavicollis, meaning 'yellow-necked'), while antennae and distal parts of legs are pale yellow. The male (the king) and the female (the queen) have a more chitinous body, as well two pairs of membranous wings, long, narrow and slightly smoky, essential in the nuptial flight. The wings are held horizontally, overlapping the abdomen when the insect is at rest, so that just one wing is visible. The females are on average a little larger than males.
Kalotermes flavicollis