A genomic study of Puerto Rico’s Africanised honey bees has found out why they are more docile than other so-called killer bees – and are far less susceptible to Varroa mite. University of Illinois post-doctoral researcher Arian Avalos, says the study found they retain most of the genetic traits of their African honey bee ancestors, but a few regions of their DNA have become more like those of European honey bees.

The researchers say these changes likely contributed to the bees’ rapid evo