In form and habit this species is very similar to Carebara diversa. However the minor workers of affinis are fractionally smaller and slightly more reddish in color. Both species have large super majors of a similar size although diversa colonies seem to maintain a larger number of majors.
Colonies of diversa are larger and much more aggressive. On average probably two – three times the size of affinis colonies. Where both species occur in the same area diversa seems dominant, with far fewer colonies of affinis being present.
In captivity affinis seems to be more difficult to establish, but once stabilized will respond well.
There are noticeable differences in behavior, but unless you have both species to study - it is difficult to tell them apart.
The following information is from observations of colonies in their natural habitat, and colonies I have kept in captivity, over the past ten years.
First and most notable is that diversa only ever has one queen in a colony. I have excavated many colonies of this species and only ever found a single queen. The queen is kept in a chamber at the very base of the colony which is often over 60 cm down. Even in young newly formed colonies the queens chamber can be 30 cm down. In comparison mature affinis colonies have multiple queens in each colony, frequently in the region of 10 -20 and sometimes even more. These queens are found in the surface chambers along with the brood.
If newly mated queens of diversa are placed together they will fight each other until only one remains, while affinis queens will agreeably cluster together to form a new colony. However, as with diversa colonies of affinis are usually founded by a single new queen, and then once the colonies are a moderate size they will accept new queens after alate flights.
The queens of diversa are larger and often 2.0-2.2 cm in size, while affinis varies from about 1.6 to 1.8 cm in size, and frequently in affinis the smaller queens are a comparable size to the largest majors.
When disturbed the queens of affinis seem to attract great attention from their workers and will be covered by a seething mass, to the point that it is difficult to see them. Although diversa queens are also heavily protected the attraction is not as great.
One of the main problems in differentiation is that the Chinese wholesalers have been selling affinis under the name of diversa for many years. This is probably because it is much easier for them to collect multiple queens from an affinis colony, than the single queen of diversa. Hence many past observations and records by hobbyists about diversa are actually about affinis.
We have several colonies available - with single or multiple queens. They are vigorous young colonies, headed by strong queens and have plenty of brood.