In mammals such as rodents that raise their young as a group, infants will nurse from their mother as well as other females, a dynamic known as allosuckling. Ecologists have long hypothesized that allosuckling lets newborns stockpile antibodies to various diseases, but the experimental proof has been lacking until now.
An in-press report in the journal Mammalian Biology found that infant Mongolian gerbils that suckled from females given separate vaccines for two different diseases wound up with antibodies for both illnesses.