What characteristic defines polymorphic ant species?

Polymorphic ant species are defined by the presence of various forms in size among individuals within a colony. This means that these species can have worker ants of different sizes, which may serve different roles in the colony. The size variation allows a polymorphic ant colony to be more flexible and efficient, as different-sized ants can perform specialized tasks based on their physical characteristics.

For instance, smaller ants might excel at tasks such as foraging and communication, while larger ants might take on roles that involve defense or heavy labor. This size diversity enhances the resilience and adaptability of the colony to varying environmental conditions and pressures.

Having a single form in size pertains to monomorphic species, which do not exhibit this diversity and typically have workers that are all similar in size. Being larger than monomorphic species is not an inherent characteristic of polymorphic species; size can vary widely within both categories. Lastly, being unable to form colonies contradicts the very nature of ants as social insects, as their life cycle and survival depend on colony formation.