11 February 2026, based on my Road Scholar birding trip to Costa Rica in January 2026
There’s a group of tropical birds in the Western Hemisphere whose lives are so closely intertwined with ants that their names include the word “ant” —> Antbird, antshrike, antvireo, antthrush, antpitta, ant-tanager, antwren. These birds don’t eat ants. Instead they follow army ant swarms to eat small prey the ants scare out of hiding. Ant-named birds are not the only ones who do this.
About 462 species of birds opportunistically feed near army ant swarms. Within this group, 16-29 species require army ants for their livelihood and don’t hunt without them. These obligate army ant followers would die of starvation if there were no army ants. The ocellated antbird (Phaenostictus mcleannani), shown at top, is one of them.
The most reliable way to see antbirds is to find foraging army ants but first you have to know something about the ants.
Army ants form nomadic colonies of 10,000 to 10 million ants. Since they have no fixed home they gather in a bivouac, a defensive interconnected “ball” with the queen, eggs and larvae in the middle surrounded by workers and soldiers.
Those that forage above ground during the day are the ones that attract the birds. Army ant foragers leave the bivouac in a long line …
… then they fan out over the forest floor and plants.
Because army ants have extremely poor vision they use their sense of smell to detect each other and sense of touch to detect their prey. As they fan out they touch everything with their antennae. If something moves it’s prey and they immediately surround, attack and dismember it. Word to the Wise: If you are out ahead of an army ant swarm and it catches up to you, Don’t Move!
Watch ant swarms, birds and researchers at work in this video from the Smithsonian Tropical Research Institute in Panama. It begins with two blue morpho butterflies winking in the forest. And then the ants and birds show up! (The video lasts 10 minutes. If you don’t have that much time the first 3-5 minutes will show you a lot.)
p.s. Yes there are more than just antbirds following the ants. Wikipedia lists others found in Panama:
Birds that frequent army-ant swarms include the white-whiskered puffbird, rufous motmot, rufous-vented ground cuckoo, grey-cowled wood rail, plain-brown woodcreeper, northern barred woodcreeper, cocoa woodcreeper, black-striped woodcreeper, fasciated antshrike, black-crowned antshrike, spotted antbird, bicolored antbird, ocellated antbird, chestnut-backed antbird, black-faced antthrush, and gray-headed tanager.[
— WIkipedia: army ant foraging