Species with unusual modes of reproduction are overrepresented among invasive organisms that are dispersed by humans across the globe and can wreak havoc wherever they land (1, 2). Invasive species thrive in disturbed habitats as well as island ecosystems, which have evolved largely in isolation and are therefore particularly vulnerable. However, upon arrival, colonizers face their own challenges: At initially tiny numbers, finding mates can be almost impossible, and inbreeding and genetic bottlenecks can be severe. Successful invaders often overcome these challenges through ingenious innovations in their reproductive biology. On page 55 of this issue, Darras et al. (3) show that the yellow crazy ant (Anoplolepis gracilipes), an invasive species that has spread across Asia and the western Pacific, features workers that are hybrids between two separate genetic lineages, and males that are genetic chimeras of the same two genetic stocks.
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