What if you could vaccinate a loved one by kissing them? Well, then you might be an insect.

Ants swap spit that contains disease-fighting compounds, so a few members of a colony can essentially immunize the rest mouth-to-mouth, says Rebeca Rosengaus, an associate professor and behavioral ecologist at Northeastern.

Termites sometimes do something similar, but their pathogen-battling material comes out the other end. Other times, they do a little dance.

Read the full story at News@Northeastern.

Photo by Matthew Modoono/Northeastern University.