Birds rub ants on their feathers to bathe in the insects’ defensive chemicals, which may clean and protect their plumage, soothe itchy skin, and make the ants safer to eat. This “ant spa” ritual, called anting, is a multi-purpose grooming behavior that scientists are still working to fully understand.
What Exactly Is Anting?
Imagine a robin or crow dropping into an anthill, fluffing its feathers and spreading its wings as if sunbathing in a living carpet of insects. That’s anting.
In this behavior, a bird deliberately coats its feathers with ants or other small insects. Some birds practice active anting—picking up ants in the bill and wiping them along the wings and tail. Others use passive anting, squatting or lying in a swarm so the ants crawl through their plumage.
More than 200 species—from starlings and thrushes to ravens—have been seen doing this grooming ritual, known as anting. It sits alongside dust baths, water baths, and sunning as part of a bird’s self-care toolkit.
The Chemical Bath: Ants as Feather Cleaners
Most “anting ants” belong to groups that spray formic acid, a sharp-smelling chemical they normally use for defense. When a bird invites these ants into its feathers, it is essentially taking a chemical bath.
Formic acid and related compounds can slow the growth of bacteria and fungi that weaken feathers and may irritate lice and mites enough to flush them out of hiding. Researchers think this blend of ant secretions plus the bird’s saliva could help keep feathers in top shape and limit damage from microbes and tiny parasites, though evidence for parasite control is still modest and mixed in studies of anting behavior.
Scientists don’t fully agree on whether parasite control or feather hygiene is the main payoff, and the answer may differ from species to species.
Snack Prep and Spa Day: Other Possible Reasons
Some birds rub ants on their feathers and then eat them. One idea is that rubbing ants on the feathers makes the insects fire off their formic acid first, “using up” those defenses so the ants are less irritating—and more palatable—once swallowed. This food-preparation angle has been especially noted in ant-loving birds like starlings.
Another hypothesis is comfort: during molt, when new feathers are pushing through the skin like tough new hair, anting might soothe itchiness or stimulate growth. A third idea is that it simply feels good, a kind of sensory self-stimulation with no big survival benefit at all.
Behavior experts increasingly frame these quirky acts in an evolutionary way, asking what mix of hygiene, feeding, and comfort benefits could make anting worth the effort across many species—an approach illustrated in works like modern studies of bird behavior.
How to Spot Anting in Your Backyard
You don’t need a wilderness lodge to see anting—you just need patience and a good view. A patch of lawn, a sidewalk crack, or a corner of your local park can host the drama.
Try this:
- Pick a quiet spot with an anthill or where small ants regularly patrol.
- Watch during warm daylight hours when birds are actively foraging.
- Look for a bird dropping down, spreading its wings and tail, and wriggling in place for several minutes while ants swarm over it.
A simple “nature out your window” session—5 to 10 minutes of still, quiet watching—can be enough to catch unusual behaviors like this right outside your home. Binoculars help, but your best tools are patience and curiosity.
Try a Digital Naturalist Challenge
Here’s a fun experiment for your inner Digital Naturalist:
- Listen first. When you see a bird near an anthill, record its calls with your cell phone and later run the sound through an AI ID tool such as BirdNET to confirm the species.
- Watch the body language. Note how long the bird ants, which body parts it focuses on, and whether it eats the ants afterward.
- Log your sighting. Upload a photo or written note of the behavior to a community science platform like iNaturalist. Use the word “anting” in your description so other birders can find it.
With each observation you’re not just watching a weird bird bath—you’re helping illuminate a still-mysterious behavior that blurs the line between spa treatment, pest control, and dinner prep. That’s the joy of digital birding: the more closely you look, the stranger and more wonderful your everyday birds become.
