If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.


Biological Chemistry


Ants surprise scientists with their medical attention, and cuddling chickens could knock people off their perches

by Alex Scott
April 16, 2018 | A version of this story appeared in Volume 96, Issue 16


Paramedic ants

A paramedic ant treating another ant.
Credit: Julius Maximilian University of Würzburg
Insect rescue: A paramedic ant cleans the wound of an ant hurt in battle.

Ants have just become even more amazing. Scientists already knew that they can carry material up to 50 times their body weight, that they farm insects for food, and that they survived the Cretaceous-Tertiary extinction that saw off the dinosaurs. Now, Erik Frank, a behavioral ecologist at the University of Lausanne, along with colleagues at Julius Maximilian University of Würzburg, have discovered that African Matabele ants—Megaponera analis—dress the wounds of their injured comrades and apply what is thought to be an antibiotic (Proc. R. Soc. B 2018, DOI: 10.1098/rspb.2017.2457).

This paramedic activity is particularly useful after the Matabele ants take on termites, their favorite but feisty grub, which they go hunting for whenever they get hungry. The trouble with the tasty termites is that they have soldiers with powerful jaws that can easily snip off an ant’s limb in a fight.

To limit colony losses during epic termite battles, the ants have developed a paramedic service. Once injured, Matabele ants send an SOS by secreting smelly dimethyl disulfide and dimethyl trisulfide, which signal their fellow ants to carry them back to their nest. There, the ants treat the injured by repeatedly licking their wounds. “We suppose that they do this to clean the wounds and maybe even apply antimicrobial substances with their saliva to reduce the risk of bacterial or fungal infection,” Frank says.

Without such attendance, 80% of the injured ants die within 24 hours; after receiving medical treatment for an hour, only 10% succumb to their injuries.

Frank’s hypothesis that paramedic ants administer antibiotics is given credence in a study led by Clint A. Penick of Arizona State University published in February in the journal Royal Society Open Science (DOI: 10.1098/rsos.171332). In the study, Penick and colleagues identified 20 ant species that secrete antimicrobial compounds to prevent the spread of disease. Furthermore, in a 2017 study, biologists at the University of East Anglia and the John Innes Centre identified antibiotics named formicamycins in colonies of the African ant species Tetraponera penzigi that are effective against bacterial human pathogens, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, that have grown resistant to commercial antibiotics (Chem. Sci. 2017, DOI: 10.1039/c6sc04265a). When it comes to untreatable infections, ants really could be making the perfect “ant-idote.”


Hazards of chicken hugging

A woman cuddling a chicken.
Credit: Shutterstock
Stealing kisses: A peck on the cheek with consequences.

For people seeking to avoid nasty infections such as Salmonella, petting, hugging, and even kissing chickens should remain at the bottom of their pecking order, according to recent findings of the U.S. Centers for Disease Control & Prevention. Some 1.2 million Americans contract Salmonella every year. Infected food is usually the source, but infection via chicken hugging has become a major cause, the agency squawks.


Megin Nichols, a Salmonella and Escherichia coli expert at CDC, estimates that in 2017 about 7% of people in the U.S. who reported contracting Salmonella from homegrown fowl had recently kissed their chickens, while 16% of sufferers had been snuggling with them.

Chickens, it turns out, carry Salmonella bacteria, but adaptations long ago mean that the birds are immune to them. Contrastingly, Salmonella infections can really knock humans off their perches. Nichols blames a surge in popularity of backyard coops and lack of awareness about the hazards of chicken cuddling for the rise in petting-related Salmonella cases on.

Last year had the highest number of Salmonella cases from poultry ownership yet, according to Nichols. CDC is not counting its chickens when it comes to solving the problem: It is calling on owners to wash after handling their chickens and ensure that any pecks on the cheek remain nothing more than a flight of fancy.

Alex Scott wrote this week’s column. Please send comments and suggestions to


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.