Question

What does it mean by social insects

Answer 1

Social insect : an insect (such as a termite or bee) that lives in a colony or community with other individuals of the same species
… a number of other entomologists prefer to view ant colonies and the societies of other social insects as more like superorganisms than communities of individualized organisms. —Robert L. O'Connell
The evolution of worker behavior in the social insects is usually explained by kin selection: although workers do not produce offspring, they do reproduce their genes by aiding the reproduction of relatives. —David C. Queller et al.