Melissotarsus weissi nest in tree bark with symbiotic diaspidid scale insects. Kibale Forest, Uganda

Odontomachus bauri. Trap-jaw ants are normally thought of as predators, but they also tend honeydew-producing insects. Gamboa, Panama

Argentine ants (Linepithema humile tending scale insects on an orange tree in suburban California. Davis, California, USA