Odontomachus clarus nurse worker tenderly caring for a larva (Arizona).

A defining feature of many social insects is an unusual antennal form.  The base segment is elongated such that the antennae take on a shape rather similar to a human arm. What’s up with this “elbowed” appearance?

Quite simply, the kink allows the insect to feel with her antennae what she is holding in her mouth. A useful trick for social insects that care for their young!

(In case you’re wondering, I am currently assembling a lecture on ants for the IB109 class…)