Being able to distinguish nest mates from invaders is absolutely critical, Ben-Shahar says.

本-沙哈尔说，能够从入侵者中区分出巢友是绝对关键的。

Shahar said 18 to 30-year-olds were more likely to have the skull bumps than older generations.

沙哈尔表示，相比老一代，18到30岁的人更有可能隆起骨块。

Washington University biology professor and co-author Yehuda Ben-Shahar says the microbes are changing the bees physiologically and controlling their complicated social behaviors.

华盛顿大学生物学教授兼合著者耶胡达·本·沙哈尔表示，这些微生物正在从生理上改变蜜蜂，并控制它们复杂的社会行为。