Collective behaviors are present across many different animal groups: schools of fish swimming in a swirling pattern together, large flocks of birds migrating through the night, groups of bees coordinating their behavior to defend their hive. These behaviors are commonly seen in social insects where as many as thousands of individuals work together, often with distinct roles. In honey bees, the role a bee plays in the colony changes as they age.

Researchers often study the genomes of individual organisms to try to tease out the relationship between genes and behavior. A new study of Africanized honey bees reveals, however, that the genetic inheritance of individual bees has little influence on their propensity for aggression. Instead, the genomic traits of the hive as a whole are strongly associated with how fiercely its soldiers attack.

The findings are reported in the Proceedings of the National Academy of Sciences.

Honey bees that guard hive entrances are twice as likely to allow in trespassers from other hives if the intruders are infected with the Israeli acute paralysis virus, a deadly pathogen of bees, researchers report.

Their new study, reported in the Proceedings of the National Academy of Sciences, strongly suggests that IAPV infection alters honey bees’ behavior and physiology in ways that boost the virus’s ability to spread, the researchers say.