Are bats draining my hummingbird feeder at night?

The short answer

• The US has three nectar-feeding bats: the lesser long-nosed bat, the Mexican long-tongued bat and the Mexican long-nosed bat. All three live along the Mexican border, so a feeder drained overnight in Ohio or Oregon is not a bat.
• In Tucson, the bats generally arrive in August or early September and leave in the second week of October (US Fish and Wildlife Service). A few stay through winter.
• The lesser long-nosed bat came off the federal endangered list on 18 May 2018. The Mexican long-tongued bat was never listed. The Mexican long-nosed bat is endangered, and swabs of hummingbird feeders have recently found its DNA in southeastern Arizona.
• To stop it, bring the feeder in at dusk and hang it again before first light. Hummingbirds lose nothing, and no baffle or gadget keeps out an animal that flies.
• Turn patio fans off at night if a feeder hangs near one, and never pick up a grounded bat with bare hands. Bats cause most US human rabies deaths (CDC).

Only if you live along the Mexican border, and mostly only from late August to mid-October. The US Fish and Wildlife Service (FWS) counts three migratory nectar-feeding bats in the United States: the lesser long-nosed bat, the Mexican long-tongued bat and the Mexican long-nosed bat. Between them they reach southern Arizona, southwestern New Mexico, the Big Bend country of Texas and the southernmost edge of California. There, a hummingbird feeder that is full at dusk and empty at dawn, still hanging and undamaged, is almost certainly bats. Anywhere else it is not a bat, and the night raiders guide is where to look.

Two stories circulate. One says bats of all kinds drink from hummingbird feeders. The other says the bats at your feeder are endangered. Both are wrong as usually told. FWS counts only three nectar-feeding bats in the country, and Arizona Game and Fish told KOLD News that most of Arizona's 28 bat species eat insects. And the bat most pages call endangered, the lesser long-nosed bat, came off the federal list in 2018. The endangered one is the third species, and DNA swabbed off hummingbird feeders has only recently shown it using them.

Is it bats? A one-night check#

Bats leave no damage, so the morning scene is mostly the absence of anything else.

1. Tape the level at dusk. Mark the nectar line and read it again at first light. The Tucson volunteers who track these bats for FWS do exactly this, measuring nectar in the evening and again in the morning.
2. Look at the feeder. Still hanging, upright, ports intact: that fits a bat. Unhooked, tipped or chewed is a raccoon or a bear. A feeder on an unbaffled pole may also have had an opossum on it.
3. Go out with a light. Shine a flashlight on the feeder from a few yards away. The Forest Service says these bats drain feeders "before first light," so a late look beats an early one.
4. Rule out daytime losses. If the level also falls in the afternoon, an inverted bottle may be dripping in the sun, the fault a saucer feeder avoids, or ants and wasps have found it.

The Pima County Public Library describes how the bats drink. They cannot hover the way a hummingbird does, so a bat stalls in front of the port, licks up to six times a second, and flaps off as it begins to fall.

Where and when#

Sources: FWS, the 2018 Federal Register rule, Texas Parks and Wildlife, Pima County, Arizona Game and Fish, and the 2026 swab dataset described below.

Timing is the strongest clue. The 11-year Tucson study by Fleming, Richardson and Scobie, published in 2021, found that most bats of both common species visited feeders between late August and late October, and that some kept coming through the winter. A feeder drained overnight in Tucson in September is bats. One drained in June, outside the borderlands, is not. When to run feeders for the birds themselves is in the hummingbird feeder timing guide, and the rest of the autumn routine in fall bird feeding.

Which bat is endangered, and why the pages disagree#

The confusion is mostly about dates.

• Lesser long-nosed bat. Listed in 1988, when the count was under 1,000 bats at about 14 known roosts. The Federal Register rule removing it was published on 18 April 2018 and took effect on 18 May 2018, with about 200,000 bats at about 75 roosts. Stories from before 2018, including the patio fan warning below, rightly call it endangered. They are simply old.
• Mexican long-tongued bat. Never on the federal list. Texas Parks and Wildlife calls it a former Category 2 candidate, and Pima County says the Bureau of Land Management and the Forest Service treat it as a species of concern. A Forest Service pollinator page still says both bat species "have been placed on the federal endangered species list." For this one, that is wrong.
• Mexican long-nosed bat. Federally endangered since 30 September 1988 and endangered in Texas. Arizona Game and Fish confirmed it in southeastern Arizona from saliva residents swabbed off hummingbird feeders, and calls it the state's only bat listed under the Endangered Species Act. Bat Conservation International says volunteer swabs of agave flowers and feeders gave the species' "northernmost and westernmost detections," and the Associated Press reported in February 2026 that it reaches the fringe of New Mexico's Gila National Forest. The AP put the remaining population at fewer than 10,000.

You cannot tell these apart by flashlight. In southeastern Arizona and southwestern New Mexico, the bat at your feeder could be the endangered one.

Keep feeding, or stop it#

Both are reasonable. Pick one and do it properly.

To keep feeding bats and birds. Refill each morning. The Tucson study concluded that feeders have "substantially increased" the food available to nectar bats before migration, and Texas Parks and Wildlife says feeders may help sustain bats that arrive early or stay into winter. Use the same 4:1 nectar: no source we read gives a separate bat recipe. A feeder emptied nightly is refilled daily, so wash it at each refill by the routine in how to clean a bird feeder. Around 100 Tucson volunteers a year send their dusk and dawn readings to Arizona Game and Fish, FWS says.

To stop it. Bring the feeder in at dusk and hang it again before first light. Hummingbirds do not feed in the dark, and they feed within minutes of dawn, so the morning hang is the one that matters. Nothing else works on an animal that flies to the port. A pole baffle, as in baffles and poles, stops climbers, and an ant moat stops crawlers; neither touches a bat. Do not smear anything sticky, oily or scented on the ports. Whatever stops a bat reaches the hummingbirds first.

With two feeders, use the frost swap: one comes in at dusk, a clean full one goes out at dawn, as the nectar freezing point page sets out.

Two things that hurt someone#

The patio fan. In September 2017, Arizona Game and Fish told KJZZ that lesser long-nosed bats drawn to patio hummingbird feeders in southern Arizona were being killed by fans. Its advice: "turn off the porch fans at night." Do that, or move the feeder away from the fan.

The grounded bat. The CDC says contact with infected bats is the leading cause of human rabies deaths in the United States, at least 7 in 10 of them. A bat drinking from a feeder is not contact. A bat on the patio floor that someone picks up is. The CDC's advice is to stay away from wildlife, so keep children and pets away from it. If anyone is bitten or scratched, wash the wound with soap and water and seek medical attention urgently.

It throws off your hummingbird count#

If you estimate birds from nectar drunk, as in how many hummingbirds are at my feeder, bats break the arithmetic. At that page's working figure of about 6 birds per fluid ounce drunk per day, 8 fl oz lost overnight reads as roughly 48 phantom hummingbirds, on top of whatever Anna's and migrants are really there. In bat season, measure from first light to dusk only, or take the feeder in at night while you count.

Where this page stops#

• Outside the borderlands. No nectar bat lives in the East, the Midwest, the Pacific Northwest or Canada. A night drain there is a mammal or a leak.
• Oriole and fruit feeders. The bats' natural diet includes cactus fruit, but none of our sources tested whether they take jelly from an oriole feeder, so this page makes no claim.
• Mexico. The statuses above are US federal and Texas rules only.

For any other symptom in the yard, the problems section matches it to a cause.

Frequently asked questions#

Do bats drink from hummingbird feeders?

Yes, but only nectar-feeding bats, and the US has three of them: the lesser long-nosed bat, the Mexican long-tongued bat and the Mexican long-nosed bat. They live in southern Arizona, southwestern New Mexico, the Big Bend country of Texas and the southernmost edge of California. FWS counts only those three nectar-feeding bats in the US, and Arizona Game and Fish says most of Arizona's bat species eat insects.

How do I keep bats off my hummingbird feeder?

Bring it indoors at dusk and hang it again before first light. Hummingbirds do not feed in the dark, and they feed within minutes of dawn, so the timing costs them nothing. A bat flies straight to the ports, so baffles, moats and pole tricks do nothing against it. Do not coat the feeder with anything sticky or oily: that harms the hummingbirds first. Many people in Tucson keep the feeder up and refill it each morning instead.

Are the bats at my hummingbird feeder endangered?

Probably not, but possibly. The lesser long-nosed bat, the one most often named, was removed from the federal endangered list in 2018, after its count rose from under 1,000 to about 200,000. The Mexican long-tongued bat was never federally listed. The Mexican long-nosed bat has been endangered since 1988, and swabs of hummingbird feeders have found its DNA in southeastern Arizona, and swabs of feeders and agaves farther north in New Mexico than it was known. You cannot tell the three apart in a flashlight beam.

Is it dangerous to have bats at my hummingbird feeder?

Not if you leave them alone. The CDC says contact with infected bats is the leading cause of human rabies deaths in the US. A bat drinking from a feeder is not contact. A bat on the ground, or one you have to pick up, is. Stay away from it, as the CDC advises for all wildlife. If anyone is bitten or scratched, wash the wound with soap and water and get medical attention urgently. The other real risk is to the bats: Arizona Game and Fish has found them killed by patio fans near feeders.

Why is my hummingbird feeder empty every morning?

Tape the nectar level at dusk and look again at first light. If it dropped overnight and you live along the border in late summer or fall, nectar bats are the likely cause. Anywhere else, check for a raccoon, which unhooks or tips the feeder, an opossum on an unbaffled pole, or a bear. If the level also falls during the day with nobody drinking, an inverted bottle may be dripping in the sun, or ants may have found it.

Sources and further reading

1. Community engagement and collaboration: conservation of the lesser long-nosed bat US Fish and Wildlife Service One of three migratory nectar-feeding bat species in the US; Tucson feeder volunteers measure nectar in the evening and morning; bats generally arrive in August or early September and depart the second week of October, with brief sightings in April or May; around 100 volunteers a year
2. Removal of the Lesser Long-Nosed Bat From the Federal List of Endangered and Threatened Wildlife (83 FR 17093) Federal Register, via GovInfo Published 18 April 2018, effective 18 May 2018; fewer than 1,000 bats and about 14 roosts at listing in 1988, about 200,000 bats and about 75 roosts at delisting; hummingbird feeder citizen science in Tucson; post-delisting monitoring of at least 5 years
3. "Free" food: nectar bats at hummingbird feeders in southern Arizona (Fleming, Richardson and Scobie 2021, Journal of Mammalogy) BioOne 2008 to 2018, 50 to more than 100 households a year; most bats of both species visited between late August and late October, some through winter; feeder use spread over most of Tucson and its suburbs; feeders have substantially increased food for nectar bats before migration
4. Data from: Hummingbird feeders can provide eDNA for detection of nectar-feeding bats (Riley et al. 2026) Dryad 12 citizen scientists in Arizona and New Mexico took 306 feeder swabs in 2023 and 2024; lesser long-nosed bat on 300, Mexican long-tongued bat on 274; Mexican long-nosed bat detected near Portal, Arizona
5. Meet Arizona's new bat species Arizona Game and Fish Department Mexican long-nosed bat confirmed in southeastern Arizona from saliva swabbed off hummingbird feeders; Arizona's only bat listed under the Endangered Species Act; the state's 29th bat species
6. Agave or bust! Mexican long-nosed bats head farther north in search of sweet nectar Associated Press (Susan Montoya Bryan), via WKMG Feeder swabbing in Silver City, New Mexico, 5 Sept 2025; detections on the fringe of the Gila National Forest; fewer than 10,000 bats remain; listed as endangered in 1988
7. Mexican Long-nosed Bat (Leptonycteris nivalis) Texas Parks and Wildlife Department Federally endangered, listed 30 Sept 1988, and endangered in Texas; southwestern New Mexico, Big Bend and the Chinati Mountains; northern roosts June through August
8. Mexican Long-tongued Bat (Choeronycteris mexicana) Texas Parks and Wildlife Department Former Category 2 candidate species; rare in Texas; arrives in May, leaves in October and November; feeders may help sustain bats arriving early or staying into winter
9. Mexican Long-Tongued Bat Pima County 81 to 103 mm, 10 to 25 g; California to Texas; heads south October to November; readily feeds from hummingbird feeders; species of concern for BLM and the Forest Service
10. Mexican Long-Tongued Bat: Nectar-Feeding Bats? USDA Forest Service Range into southernmost California, Arizona, New Mexico and Texas; drains feeders before first light; the page's statement that both bat species are federally listed is out of date
11. Bats and Hummingbird Feeders Pima County Public Library Bats cannot hover, stall and lick up to six times a second; one Mexican long-tongued bat took 0.67 oz in 106 minutes, 96 percent of body weight (citing the Arizona Daily Star)
12. Significant range expansion confirmed for endangered bat Bat Conservation International eDNA from agave flowers and hummingbird feeders, collected by community scientists, gave the northernmost and westernmost detections of the endangered Mexican long-nosed bat, including the first definitive Arizona record
13. Researchers ask for help monitoring nectar-eating bats in southern AZ KOLD News 13 Arizona Game and Fish: bats drain feeders overnight in late summer and early fall; two nectar species locally; most of Arizona's 28 bat species eat insects
14. Endangered bats have no chance against patio fans in southern Arizona KJZZ Arizona Game and Fish (Mark Hart): bats drawn to patio hummingbird feeders are being killed by fans; turn porch fans off at night (19 Sept 2017)
15. About Rabies Centers for Disease Control and Prevention Bats cause at least 7 in 10 US human rabies deaths; wash bites and scratches and seek medical attention urgently