Social insects (4)
'social insects' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ants that I've seen before include "24 [INSECT] s" , "Tiny insects that live in colonies" , "Inhabitants of a formicary" , "Soldiers" , "workers found returning" .)
(Other definitions for termites that I've seen before include "Destructive workers" , "Ant-like social insect that feeds on wood" , "Ant-like insects that feed on wood" , "Flightless insects living in mounds" .)