Crematogaster castanea tricolor

An arboreal carton nest of Crematogaster castanea tricolor. This nest is about the size of a softball. St. Lucia, KZN, South Africa

An Oecophylla smaragdina weaver ant guard hangs from the bottom of her nest, alert to any photographers that might try anything brash. Cape Tribulation, Queensland, Australia

An armored tree ant (Cataulacus huberi) pauses to groom her legs and antennae. Ants are extremely clean insects. Kibale forest, Uganda

Pseudomyrmex apache Northern California, USA

Podomyrma adelaidae Yandoit, Victoria, Australia

Cataulacus brevisetosus St. Lucia, KZN, South Africa

Temnothorax gallae is an ecologically specialized ant that nests in pre-existing cavities of manzanita trees. Jasper Ridge, California, USA

Colobopsis papago

Ants that nest in trees often have bizarre adaptations for plugging the entrances to their nests. This Colobopsis papago queen has a cork-like head that doubles as a door. Santa Rita Mountains, Arizona, USA

Atopomyrmex mocquerysi is a conspicuous arboreal ant in African forests. St. Lucia, KZN, South Africa

Camponotus mus Correa, Santa Fe, Argentina

A colorful Calomyrmex laevissimus worker forages along a leaf in an Australian rainforest. Mungkan Kandju National Park, Queensland, Australia

Winter leaf drop reveals a number of old Oecophylla smaragdina green tree ant nests. The ants have moved on, but the signs of their presence remain. Tree ants are polydomous, so the nests likely all belonged to a single colony. Cape York Peninsula, Queensland, Australia

This ant nest- crafted from living leaves in an African forest- is held together by silk spun by the larvae. This unusual nesting habit has earned these insects (Oecophylla longinoda) the common names 'weaver ant' and 'tailor ant.' St. Lucia, KZN, South Africa

Oecophylla smaragdina, the green tree ant of northern Australia. Cape York Peninsula, Queensland, Australia

Oecophylla longinoda St. Lucia, KZN, South Africa

Oecophylla longinoda St. Lucia, KZN, South Africa

Friend or Foe? Oecophylla longinoda workers encounter each other on a tree branch and take a quick sniff of the other's scent. St. Lucia, KZN, South Africa