Socially parasitic ant queens chemically induce queen-matricide in host workers

Matricide - the killing of a mother by her own genetic offspring - is rarely observed in nature, but not unheard-of. Among animal species in which offspring remain with their mothers, the benefits gained from maternal care are so substantial¹ that eliminating the mother almost never pays, making matricide vastly rarer than infanticide. Here, we report matricidal behavior in two ant species, Lasius flavus and Lasius japonicus, where workers kill resident queens (their mothers) after the latter have been sprayed with abdominal fluid by parasitic ant queens of the ants Lasius orientalis and Lasius umbratus.