Problem Solving
Ants in a Hummingbird Feeder
Ants in a nectar feeder are two problems stacked: an ant highway you can break with plain water, and a leak that built the highway in the first place.
The short answer
- A water-filled ant moat hung above the feeder is the whole solution. Ants cannot cross a quarter inch of water, and nothing about it touches the birds.
- Never use petroleum jelly, cooking oil, grease, sticky tape or insecticide anywhere on or near a feeder. Oil mats feathers so a bird cannot waterproof or insulate itself, and that is often fatal.
- If ants found you, the feeder is probably leaking. Drips come from a cracked gasket, an overfilled bottle heating in the sun, a loose base or a chewed port.
- Dead ants in the nectar mean dump it, wash the feeder and start over. Ants carry formic acid and bacteria into the solution and hummingbirds avoid fouled nectar.
- Saucer-style feeders resist ants better than inverted bottles because the nectar sits below the ports and cannot drip out.
The answer is a water-filled ant moat hung above the feeder, plus finding whatever is leaking. Ants cannot swim across a quarter inch (6 mm) of standing water, so a small cup on the hanger ends the trail on the first afternoon, and nothing about it can harm a bird.
Everything else people try either fails or is dangerous. Oil, petroleum jelly and sticky tapes on the hanger get onto feathers. Insecticide near a nectar feeder poisons the birds it is supposed to protect, along with the small insects that hummingbirds actually eat.
This page covers how a moat works and where to hang it, how to trace the leak that recruited the ants, what to do with fouled nectar, and the feeder designs that avoid the problem entirely.
Why ants find your feeder at all#
Ants forage by chemical trail. A single scout that finds sugar returns leaving a pheromone line, and within a day the whole colony is using it. Once that trail exists, it stays in use as long as the reward does.
The reward is nearly always a leak or a spill, not the ports themselves. Nectar creeping down the outside of a bottle, a drip on the pole, or sticky residue from a careless refill gives the scout something to find at nose height. A perfectly sealed feeder in the middle of open air is much less interesting.
Heat makes it worse. In an inverted bottle feeder, air trapped above the nectar expands as the sun warms it and pushes solution out through the ports, which is why a feeder that was fine in the morning is dripping by two in the afternoon.
The ant moat, and how to use it#
An ant moat is a shallow cup the hanging wire passes through. Fill it with plain water. Ants walking down the wire reach the water and turn back.
- Hang it above the feeder, between the hook and the feeder's own hanger. A moat below the feeder does nothing.
- Keep it filled. In hot, dry weather a small moat can evaporate in a day and a half, and an empty moat is just a bridge. Top it up whenever you check the nectar.
- Use water only. Not oil, not soapy water. Soap breaks the surface tension that stops the ants and can end up in the nectar.
- If ants are still getting in, they are coming up the pole or in over a branch. Move the feeder so nothing touches it but the hook.
Many hummingbird feeders now have a moat built into the cap. If yours does not, a separate moat is inexpensive, and a homemade one made from a small watertight cup and a wire works identically. The pros and cons of the different designs are in hummingbird feeders.
Never oil, never insecticide
Petroleum jelly, cooking oil, grease and sticky barrier products transfer to feathers on contact. A bird cannot preen oil out, and matted feathers stop being waterproof and stop trapping air, which kills birds in cold or wet weather. Insecticide sprayed on a pole, hook, plant or the ground near a feeder reaches hummingbirds through the nectar and through their insect prey, which is most of their protein. The reasoning is spelled out in pesticides, lawns and birds.
Finding the leak#
If ants keep coming, the feeder is feeding them. Take it down and work through this in order.
| Symptom | Likely cause | Fix |
|---|---|---|
| Sticky film down the outside of the bottle | Overfilled inverted feeder venting in heat | Fill to about two thirds; move to partial afternoon shade |
| Drip from the seam where base meets bottle | Perished, flattened or missing gasket | Replace the gasket, or the feeder if no parts exist |
| Slow weep with no obvious source | Hairline crack in plastic from UV or freezing | Replace the reservoir |
| Nectar around one port only | Cracked port collar or chew damage | Replace that part; check for rodent or squirrel damage |
| Puddle directly under the feeder | Base screwed on crooked or cross-threaded | Empty, realign, retighten evenly |
| Drips only in the afternoon | Thermal expansion, normal for bottle feeders | Switch to a saucer design |
Wipe the pole, hook and any leaf or rail the trail runs along with soapy water once you have fixed the source. That erases the pheromone line, which otherwise keeps working for days.
Saucer feeders end the argument#
In a saucer feeder, the nectar sits in a shallow basin below the feeding ports. There is no head of pressure, no thermal venting and no drip, so there is very little for an ant to find.
The same design also handles the other insect problem: because the nectar surface is lower than the port, bees and wasps generally cannot reach it while hummingbird tongues can. That is covered in bees and wasps at hummingbird feeders.
Saucers hold less nectar, which is a feature. Most yards should be putting out only a few days' worth anyway, for the reasons in cleaning a hummingbird feeder.
Move it a few feet
If a trail is established on a particular hook, moving the feeder even 6 to 10 feet (2 to 3 m) breaks it, because the ants have to scout the new position from scratch. Combine the move with a clean moat and the problem usually ends the same day. The general method is in moving a feeder without losing the birds.
What to do with ant-fouled nectar#
Dump it. Do not strain the ants out and reuse it.
Ants introduce formic acid and bacteria, and once a few have drowned, the nectar sours faster than usual. Hummingbirds are also reluctant to feed where dead insects float in the ports, so a fouled feeder can sit untouched while you assume the birds have left.
Wash the whole feeder in hot water with a bottle brush, paying attention to the ports and the gasket groove, rinse thoroughly, and refill with fresh solution made to the standard hummingbird nectar recipe: four parts water to one part plain white sugar, no dye, no honey, no brown sugar. Full cleaning intervals for hot weather are in how often to clean bird feeders.
Ants at other feeders#
Nectar is the usual target, but ants also work oriole and jelly feeders, where the sugar concentration is higher and the reservoir is open. The same moat above the hanger works, and jelly should be offered in small amounts that get eaten the same day rather than left to ferment.
Ants in a seed feeder generally mean damp seed, which is a different and more serious problem. See moldy, clumped or wet seed.
The two-part fix
Water-filled moat above the feeder, plus repair or replace whatever is dripping. Do one without the other and the ants come back within a week.
Do not fight the ants themselves#
Baiting or killing the colony is unnecessary and mostly futile. Ants are a large part of the diet of northern flickers and many other backyard birds, they aerate soil, and they will be replaced by another colony within a season. Ant granules and sprays in a yard where birds forage on the ground are a straightforward poisoning risk.
The exception is where fire ants or another aggressive invasive species is a genuine hazard to people or wildlife. That is a yard-wide management question, not a feeder question, and it should be handled well away from any feeding station.
A setup that stays ant-free#
- A saucer-style feeder with a built-in or added ant moat, kept topped up with plain water.
- Filled with two to four days of nectar at a time, no more, so nothing sits and ferments.
- Hung from a hook with nothing else touching it: no branch, no wire, no vine.
- Sited in morning sun and afternoon shade, which slows both fermentation and thermal venting.
- Gaskets checked each spring and replaced when they stop being springy.
- Cleaned every two to three days in hot weather, and the pole wiped down whenever a trail appears.
Get those six right and ants stop being an annual event. For the wider setup, including how many feeders to run and where to place them for the birds' benefit, see how to attract hummingbirds.
Frequently asked questions#
How do I keep ants out of a hummingbird feeder?
Hang a water-filled ant moat between the hook and the feeder, and keep it topped up. The moat is a small cup the hanging wire passes through; ants walking down the wire reach the water and turn back. Refill it every two or three days in hot weather because it evaporates fast, and fix any leak in the feeder so the trail is not being rebuilt from the ground up.
Can I put petroleum jelly or oil on a hummingbird feeder hanger?
No. Any oily substance transfers to feathers when a bird brushes past, and matted feathers lose their waterproofing and insulation, which can kill a bird in a cold night or a rainstorm. Birds also cannot preen it out. Use a water-filled ant moat instead, which works better and costs less.
Is it safe to spray ant killer near a bird feeder?
No. Insecticides poison hummingbirds directly through contaminated nectar and indirectly by wiping out the small insects and spiders that make up a large part of their diet, especially for nesting females and chicks. Do not spray the pole, the hook, the ground beneath, or the plants around the feeder.
Why is my hummingbird feeder leaking?
Most leaks come from four places: a hardened or missing rubber gasket, a base that is not screwed on square, a hairline crack in the reservoir, or an overfilled inverted bottle that pushes nectar out as the air inside heats and expands. Fill inverted feeders no more than about two thirds full, replace gaskets every season or two, and switch to a saucer feeder if the leak keeps returning.
Do ants hurt hummingbirds?
Not directly, but they ruin the feeder. Ants drown in the nectar, foul it with formic acid and bacteria, and hummingbirds tend to abandon a feeder with dead insects floating in it. A heavy ant trail also draws in wasps and other insects that compete more aggressively at the ports.
Does a homemade ant moat work as well as a bought one?
Yes, if it holds water and hangs above the feeder. A small plastic bottle cap or shallow container with a wire threaded through and sealed watertight does exactly what a manufactured moat does. Keep it shallow and always filled with plain water, never oil, and check it daily in hot weather.