Hummingbird Feeder Empty Overnight: What Drains It in the Dark

A hummingbird feeder empty overnight has three plausible explanations, and they are not equally likely. Most of the time the nectar went onto the ground rather than into an animal. Sometimes a raccoon took the whole thing apart. In one part of the country there is a fourth answer that is real, documented, and geographically narrow.

Work through them in that order, because the first one costs nothing to check and the last one applies to very few readers.

A hummingbird feeder empty overnight has usually leaked

A leak empties a feeder on exactly the schedule people describe: quietly, overnight, with nothing to see in the morning.

Nectar feeders leak for reasons that have to do with heat and pressure rather than damage, which is why a feeder that was fine in May starts dripping in August. That mechanism, and what to do about it, is already covered on this site because it is also the reason ants find a feeder: the leak is the cause, not the insects.

The check takes ten seconds. Look at the ground and the pole directly under the ports in the morning. Wet soil, a sticky pole, or a trail of ants means the nectar left through the bottom of the feeder, not through anything's mouth.

If you want to be certain, hang the feeder over a dry paved surface for one night. A puddle settles it.

What is emptying my hummingbird feeder at night, if not a leak?

Raccoons, in most of the country, and they are not subtle about it.

A raccoon that can reach a nectar feeder does not sip from the ports. It takes the feeder down, opens it, or empties it in one go, and the evidence is usually a feeder on the ground or hanging crooked. Everything about excluding them, including the pole diameter and baffle length that actually work, is in how to keep raccoons off feeders, and the first recommendation from three separate wildlife agencies there is the same one that applies here: bring it in at night.

That single habit resolves the raccoon version and the bat version at once, which is why it is worth trying before diagnosing anything.

Do bats drink from hummingbird feeders?

Yes, and this is the answer that is both true and badly overused, because it is true in a small part of the United States.

Audubon reports it directly, from suburban Tucson: The stealthy, winged creatures arrive at night, seeking backyard hummingbird feeders. The species is named: The nectar is meant for avian visitors, but in the twilight hours, it is lesser long-nosed bats that feast on the sweet liquid.

The pattern matches the complaint exactly: They take over Marilyn Hanson's feeders shortly after sunset, pausing to speed-sip the nectar and vanishing as swiftly as they appear at her suburban Tucson, Arizona, home. By morning, the feeders are drained.

Now the part that most articles leave out. This bat is a desert specialist with a specific range and a specific season.

Audubon: Unlike other bat species that eat insects, lesser long-nosed bats ( Leptonycteris yerbabuenae ) feed solely on flowers and desert fruit. They arrive on a migration: Each spring, they migrate hundreds of miles, following a northbound "nectar trail" of blossoming agaves and saguaros, which they also pollinate. Tens of thousands of them settle in southern Arizona.

And there is a season attached, from the volunteers who monitor them: The volunteers start seeing bats in their yards as early as July and bid them farewell in late October.

The wider context is what settles it for most readers. The US Fish and Wildlife Service: There are over 45 species of bat found in the US including US territories and commonwealths with the majority feeding primarily on insects.

So if you are in Tucson in September and the feeder is dry every morning, bats are a reasonable first guess. If you are in Ohio in May, they are not, and the leak is still the likeliest answer.

The moth people mean

There is a nocturnal nectar feeder that turns up almost everywhere, and it is not draining anything.

The US Fish and Wildlife Service describes the shift plainly: Pollination does not stop at sunset with bats, moths, beetles and other insects collecting pollen and nectar at night. One of those moths has a name that guarantees confusion: the agency captions a photograph of a White-lined sphinx moth or hummingbird moth (Hyles lineata) nectaring on Rocky Mountain beeplant.

A hummingbird moth at dusk is genuinely hard to tell from a very small hummingbird, and people do report them at feeders. We could not find a source that puts sphinx moths at nectar feeders in quantities that would empty one, and the arithmetic makes it unlikely at the volume people describe. Treat this as an identification, not a cause.

Why is my hummingbird feeder emptying so fast in daylight?

Worth separating from the overnight version, because the causes do not overlap.

Fast daytime consumption is usually the birds, and in late summer it is many more birds than you had in June, because young of the year are flying and migrants are moving through. That is also the season when nectar spoils fastest, which means a feeder emptying quickly in August is doing you a favor by not sitting long enough to ferment.

Heat does a smaller share of the work through evaporation, and heat is also what starts most leaks, so a feeder losing volume in a hot week may be doing all three at once.

Questions people ask

Why is my hummingbird feeder empty every morning? Most often a leak. Check the ground under the ports for wet soil or ants before assuming an animal. Raccoons are the next candidate, and in the desert Southwest nectar-feeding bats are documented at feeders.

What is emptying my hummingbird feeder at night? A leak, a raccoon, or, in southern Arizona between July and late October, lesser long-nosed bats.

Do bats drink from hummingbird feeders? Yes, in the part of the country where nectar-feeding bats live. Audubon documents lesser long-nosed bats draining feeders overnight in suburban Tucson. Most US bat species eat insects rather than nectar.

Should I stop feeding if bats are visiting? The Audubon account describes residents refilling deliberately and monitoring the visits as part of a long-term study that contributed to the species being removed from the endangered list. That is the opposite of a problem to be solved.

How do I stop whatever it is? Bringing the feeder in at dusk and rehanging it at dawn ends the raccoon version and the bat version together, and it costs nothing to test for a few nights.

Could it be evaporation? Some, in heat, but evaporation does not empty a feeder overnight on its own. It does contribute to the pressure changes that start leaks.

Is a hummingbird moth drinking it? Almost certainly not in any volume. The white-lined sphinx moth is often mistaken for a hummingbird at dusk, but nothing we found documents moths emptying a feeder.

Hummingbird feeder empty overnight: the short version

A hummingbird feeder empty overnight is a plumbing problem far more often than a wildlife problem. Look under the feeder first, because a leak that drains a reservoir by morning leaves a mark on the ground and costs nothing to confirm.

If the ground is dry, bring the feeder in at dusk for a few nights. That one habit distinguishes between the animals without requiring you to identify any of them, and it is the standard first recommendation for raccoons anyway.

And if you live in southern Arizona in late summer, consider that the drained feeder may be something worth keeping. The people whose feeders those bats empty every night refill them on purpose, and their records helped get the species delisted. A hummingbird feeder empty overnight is a plumbing question in most of the country and a wildlife one in very little of it.

This article contains no affiliate links. Where this article says no source documents moths emptying a feeder, that is a statement about what we could find. Nothing here is a first-hand sighting: every claim about bats and moths is attributed to the source that published it.