A Camponotus (Myrmmobrachys) ant feeds from the nectaries of an Inga plant. The plant presumably gains protection from herbivorous insects by attracting ants in this manner.

Jatun Sacha reserve, Napo, Ecuador
Dolichoderus scabridus tending an extra-floral nectary.

Adelaide, South Australia
Sonoran desert cacti are frequently covered in ants.  Cacti provide ants with nectar- a ready food supply in a harsh environment- in exchange for protection from herbivorous insects.  Here, two Crematogaster opuntiae acrobat ants exchange nectar they have gathered from a chain-link cholla.

Tucson, Arizona, USA
Pseudomyrmex spinicola acacia ants guarding a nest entrance.  This species has a painful sting and a much more aggressive temperment than most other Pseudomyrmex, an effective deterrent to large vertebrate herbivores.  

Chiriqui, Panama
Not all of the thorns on a swollen-thorn Acacia house the ants' larvae, but those that do are heavily guarded.  Here, Pseudomyrmex spinicola patrol a nest entrance, ready to use their stings if the photographer approaches too close.  

Chiriqui, Panama.
The hollow stem of a Cecropia ant-plant is divided into chambers to house fierce Azteca alfari ants. Inside, the ants raise their brood and tend to mealybugs. 

Gamboa, Panama
Cutting open the surprisingly soft flesh of an Acacia thorn reveals larvae and pupae of the Pseudomyrmex spinicola acacia ant.  

Chiriqui, Panama.
Friend or Foe? Two Pseudomyrmex spinicola acacia ant nestmates evaluate each other at the nest entrance. 

Panama City, Panama
Pseudomyrmex spinicola workers harvest Beltian bodies on an Acacia tree. The tree and the ant are locked into relationship where the survival of both partners depends on the other.  The ants provide the Acacia with protection from herbivores and from competing plants, while the tree provides the ants with food and shelter.  

Chiriqui, Panama.
Not all of the thorns on a swollen-thorn Acacia house the ants' larvae, but those that do are heavily guarded. Here, Pseudomyrmex spinicola patrol a nest entrance, ready to use their stings if the photographer approaches too close.

Chiriqui, Panama.
Not all of the thorns on a swollen-thorn Acacia house the ants' larvae, but those that do are heavily guarded.  Here, Pseudomyrmex spinicola patrol a nest entrance, ready to use their stings if the photographer approaches too close.  

Chiriqui, Panama.
Not all of the thorns on a swollen-thorn Acacia house the ants' larvae, but those that do are heavily guarded. Here, Pseudomyrmex spinicola patrol a nest entrance, ready to use their stings if the photographer approaches too close.

Chiriqui, Panama.
See photo in original gallery.
all images and text © Alex Wild 2001-2013