The size-dependent division of labour in monomorphic ant Lasius niger

Abstract

In polymorphic ants, non-reproductive work is divided between morphological subcastes of workers. However, as recent studies have shown, even in monomorphic species body size can also be associated with the division of labour. We studied whether workers of the common ant Lasius niger foraging (for honey) outside the nest differ in head size from individuals working inside the nest. We found that extranidal workers were significantly larger than intranidal workers. Comparing the present result with previous studies, the relationship between function and size in monomorphic ants might be more common than previously thought. However, when studying this type of association large sample sizes are recommended in order to obtain reliable results.