Crazy ants’ strange genomes are a biological first

Male yellow crazy ants (Anoplolepis gracilipes) are all chimæras: they are composed of two warring cell lineages with two entirely different sets of genomes. Usually, an organism’s cells all carry the same genes. In yellow crazy ants, some cells carry only maternal and others only paternal genetic material. Chimærism can happen by accident in other animals, but the ants are the first known animal for which this property is an essential aspect of life — although it’s not clear why.