The shape of the anterior margin of the clypeus is sometimes important when distinguishing among different genera. The degree of eye development is variable. Some ants have an eye composed of only one facet. There are some ants which have no eye. The location and degree of development of eyes are taxonomically important.
Workers often have no ocellus.
The antenna of the worker and the female is usually composed of 12 segments, while that of the male is often composed of 13 segments. The number of segments is smaller in some genera. The segments of the antenna are numbered, beginning from the segment closest to the base. The first segment, which is called the scape, is relatively long and forms a knee-like joint with the other parts. The second and subsequent segments are collectively called the funiculus.