Is it legal for me to remove bats from my NH home myself?

It depends on timing and method. You may not seal bats out during the maternity season (approximately June–August) — doing so traps flightless pups and can violate their protected conservation status. Outside the maternity season (September–April), a homeowner may seal entry points, but a licensed Wildlife Control Operator is strongly recommended for any colony. You may never kill bats or use poison on them. If a bat bit anyone, contact NH DHHS at (603) 271-4496 before doing anything else.

I woke up to a bat in my bedroom — what do I do?

Call NH DHHS Bureau of Infectious Disease Control at (603) 271-4496 immediately. When someone is sleeping in a room with a bat, an unapparent bite cannot be ruled out, and the NH DHHS protocol treats bedroom bat contact as a potential rabies exposure. If possible, safely capture the bat (using gloves or a container, never bare hands) for rabies testing — do not release it outdoors until you have spoken with NH DHHS. Do not panic, but do not wait.

When is bat exclusion allowed in New Hampshire?

The safest exclusion window is September through April — after pups have grown and learned to fly, and before next year's maternity season. One-way bat doors can be installed in August once the pups are flying. Sealing entry points between approximately May and August is not recommended because flightless pups present in the colony would be trapped. Always confirm with a licensed WCO before starting exclusion work near these dates.

Are bats in NH dangerous?

Most bats are not rabid — but you cannot tell by looking at one. Any bat that can be easily approached may be sick, per UNH Extension. The primary hazard is rabies if any skin contact occurs; the secondary hazard is histoplasmosis if large quantities of dry guano are disturbed without PPE. The overall risk of a bat in your attic (without contact) is low, but any bat-human contact must be treated seriously and reported to NH DHHS.

What is white-nose syndrome and does it affect NH bats?

White-nose syndrome (WNS) is a fungal disease caused by Pseudogymnoascus destructans that attacks hibernating bats. It first appeared in NH in the winter of 2008–09 and devastated populations: at four of the largest NH hibernacula, bat counts crashed from 3,230 in 2009 to just 16 by 2011 — a loss of 79–100%. The little brown bat is now state-endangered in NH as a result. This is one reason bat colonies matter ecologically and are treated as species of conservation concern.

How do I tell a little brown bat from a big brown bat?

The big brown bat (Eptesicus fuscus) is noticeably larger — wingspan 12–16 in versus 9–11 in for the little brown bat — and is the species most commonly seen flying around NH neighborhoods, streetlights, and buildings at dusk. The little brown bat (Myotis lucifugus) tends to form the large maternity colonies in NH attics and barns. For control purposes, the species doesn't change the management approach — both are species of conservation concern.

What should I do if I find a bat on the ground or acting strangely?

Do not touch it. A bat on the ground that can be approached is behaving abnormally and may be ill. Keep people and pets away. If it was in contact with any person or pet, call NH DHHS at (603) 271-4496. You can contact USDA Wildlife Services (NH) at (603) 223-6832 for guidance on sick or grounded bats. A healthy bat should be nocturnal and fly normally — daytime grounding or erratic behavior warrants caution.

Can bat guano make me sick?

Yes, if disturbed in large quantities without protection. Histoplasma capsulatum, the fungus that causes histoplasmosis, can grow in accumulated bat and bird guano. Inhaling airborne spores when cleaning or disturbing old guano can cause a respiratory illness ranging from mild flu-like symptoms to serious pulmonary disease. Always wear an N95 respirator and disposable gloves when near accumulated bat guano, and consult a professional for large accumulations. Route any illness concerns to a doctor or NH DHHS — no medical dosages are provided here.

Do bats eat mosquitoes — should I want bats near my house?

Bats do consume large numbers of insects, including mosquitoes, and play a valuable ecological role. A healthy bat colony in an outbuilding or bat house is an ecological asset. The problem arises when they roost inside living spaces, where guano accumulation, entry-gap concerns, and rare rabies risk become issues. Installing a bat house nearby can give bats an alternative roost after exclusion from your attic, maintaining the ecosystem benefit while moving the colony out of your living space.

Is it legal to kill bats in New Hampshire?

No. NH bats — particularly the little brown bat (state-endangered) and big brown bat (species of conservation concern) — may not be killed or harmed. Lethal control is not a legal management option. The correct approach is one-way exclusion during the appropriate season (September–April, or August after pups are flying), followed by permanent sealing of all entry points. Any pest company suggesting lethal bat control in NH should be viewed with serious skepticism.

Little brown bat / Big brown bat · Myotis lucifugus

WildlifeNH resident

Bats in New Hampshire — ID, Signs & Safe Removal

Also called little brown myotis · big brown bat · house bat

New Hampshire bats (chiefly little brown bat and big brown bat) are protected species of conservation concern. Exclusion is legally and ethically restricted during the June–August maternity season when flightless pups would be trapped. Any bat found in a bedroom is treated as a potential rabies exposure — call NH DHHS at (603) 271-4496 immediately. Colony removal is almost always a licensed Wildlife Control Operator job.

At a glance

Little brown bat size: Body 2.5–4 in, wingspan 9–11 in, 1/8–1/2 oz; NH Fish & Game
Reproductive rate: One pup per female per year, born in June; UNH Extension
Lifespan: Up to 20–30 years; NH Fish & Game
WNS crash: 3,230 bats (2009) fell to 16 (2011) at 4 NH hibernacula — 79–100% mortality; NH Fish & Game
Maternity restriction: No exclusion May–August; use one-way doors in August after pups fly; NH Fish & Game
Bedroom contact protocol: Call NH DHHS (603) 271-4496 immediately for any bedroom bat; NH DHHS / UNH Extension

The short of it

The bat in your attic: NH's most legally complex wildlife problem

Bats are some of the most valuable wild animals in New Hampshire — a single little brown bat can consume hundreds of insects per hour — and they are some of the most legally sensitive. Both species commonly found in NH homes (the little brown bat and the big brown bat) are species of conservation concern, and white-nose syndrome (WNS) has devastated NH populations by 79–100% since it first appeared here in the winter of 2008–09.

The single most important fact for any homeowner: you cannot simply seal a bat colony out of your attic whenever you feel like it. Between approximately June and August, female bats form maternity colonies to raise their pups. The pups are flightless for weeks after birth, so sealing during this window traps and kills them — which is both unethical and legally problematic given their protected conservation status. One-way exclusion doors should be installed in August, once pups can fly, then sealed permanently.

The second most important fact: any bat found in a bedroom, or any situation where a bat could have contacted a sleeping person or child, is treated as a potential rabies exposure by NH DHHS — even if no bite was felt, because bat bites can be unapparent. Call NH DHHS Bureau of Infectious Disease Control at (603) 271-4496 immediately. Do not wait and see.

Identify it

How to identify New Hampshire bats

Two species account for nearly all bat-in-building calls in NH: the little brown bat and the big brown bat. Both have membranous wings and erratic, swooping flight — very different from birds. Seeing one flying at dusk indoors or in the attic, or finding guano below vents and eaves, are the typical first signs.

Species profile

Little brown bat / Big brown bat

Scientific name: Myotis lucifugus (little brown) / Eptesicus fuscus (big brown)
Family: Vespertilionidae
Size: Little brown: body 2.5–4 in, wingspan 9–11 in, 1/8–1/2 oz; big brown: body 4–5 in, wingspan 12–16 in, 1/2–5/8 oz
Coloration: Glossy brown above, lighter buff below; big brown bat slightly larger and paler
Habitat: Hot attics, barns, and outbuildings for maternity colonies; caves and mines for winter hibernation
Active season: ~mid-April through October; big brown bat may overwinter in buildings; little brown bat migrates to hibernacula
Diet: Insectivore — moths, beetles, mosquitoes, midges; can consume hundreds of insects per hour
Reproduction: 1 pup per female per year, born in June; pups are flightless for several weeks
Lifespan: Up to 20–30 years (one of the longest-lived mammals for their size)

Both species occur throughout New Hampshire; little brown bat is state-endangered; big brown bat is the one most commonly seen in NH neighborhoods

The tells — key ID features

Tiny body (smaller than a human hand) with a large, membranous wingspan — the combination is unmistakable.
Erratic, swooping flight at dusk — distinctly different from birds, which have smoother flight paths.
Glossy dark brown fur; the big brown bat is the species most likely seen in NH backyards and buildings.
Guano: small, pellet-like, dry, and crumbly — unlike mouse droppings, bat guano turns to powder when crushed.
Congregate in hot attic spaces and gable vents for maternity colonies May–August.

Size, to scale

The insect

Body smaller than a human thumb; wingspan 9–16 in depending on species

Compared to

Body fits in a closed fist; wingspan about the width of a standard sheet of paper (little brown) to a sheet of legal paper (big brown)

Looks bigger than it is

A bat looks much larger in flight due to its wide wingspan — the body itself is tiny.

Is it actually this? — the confusion species

Birds at dusk (swallows, chimney swifts)

How to tell — Birds have smooth, purposeful flight and feathered wings; bats have membranous wings and an erratic, jerky flight pattern.

Little brown bat vs. big brown bat

How to tell — Big brown bat is noticeably larger (wingspan 12–16 in vs. 9–11 in) and is the species most commonly seen flying in NH neighborhoods. Little brown bat is state-endangered.

What you'll notice

Signs of a problem

Bat colonies can go undetected for years in NH attics. These are the signs that bats are present and that a maternity colony may have established.

Bats seen flying out from a roofline at dusk (one or many)

What it means — An active roost in the attic, gable vent, or soffit — likely a maternity colony in summer.

Pellet-like guano accumulating below gable vents, behind shutters, or on attic insulation

What it means — A colony above; guano volume indicates colony size and duration.

Dark staining or grease marks at a vent or gap edge

What it means — The entry/exit point the colony uses regularly — their oils and guano build up over time.

Squeaking or fluttering sounds at dusk or dawn from the attic

What it means — Colony activity; pups are especially noisy in June–July before they can fly.

A single bat flying inside the living space at night

What it means — A pup or adult entered through an interior gap; treat as a potential rabies exposure if anyone was sleeping in the room.

Bat bugs (close relatives of bed bugs) found indoors after bats depart

What it means — Bats left or were excluded; their ectoparasites are now seeking a new host.

How much it matters

The real risks, calibrated

Most bats are not rabid. However, the risks associated with bats are high enough — and the legal protections significant enough — that this is rarely a DIY situation.

Overall risk

High

Rabies exposure

Severe

Onset: Any bat-human contact (bites often unapparent)

Rabies is fatal once symptomatic; any bedroom bat contact requires immediate call to NH DHHS (603) 271-4496 for post-exposure protocol guidance.

Histoplasmosis from accumulated guano

Moderate

Onset: Days to weeks after disturbing dried guano

Histoplasma capsulatum can grow in accumulated bat (and bird) guano; inhalation of disturbed spores can cause pulmonary illness. PPE required for cleanup.

Illegal exclusion during maternity season

High

Onset: Any exclusion attempt May–August

Sealing bats in during the maternity season traps flightless pups, causing them to die in the structure — and violates the conservation-concern status of NH bat species.

Bat bugs and ectoparasites

Low risk

Onset: After bats depart or are excluded

Bat bugs (Cimex adjunctus) closely resemble bed bugs and bite humans when their bat hosts are gone. Mites can also transfer.

What you can do

DIY — what works, what backfires

Bat situations have hard legal and safety limits that constrain what homeowners should attempt on their own. Here is what is safe and appropriate — and what is not.

What actually works

If a bat is loose in a room: open all windows and exterior doors, turn off lights, close interior doors, and let it find its own way out — do not swat at it.
If anyone was in the room while sleeping, or a child or pet was left alone with a bat: capture the bat safely (gloves or container — never bare hands) for rabies testing and call NH DHHS at (603) 271-4496 immediately.
Cap open chimneys and seal obvious large gaps OUTSIDE of the maternity season (September through April is the safest window).
Install a bat house on a south- or east-facing pole at least 15 ft high to give displaced bats an alternative roost — good for the ecosystem.
Hire a licensed Wildlife Control Operator (WCO) for any colony exclusion or any work during or near the maternity season.

What backfires

NEVER seal bat entry points between approximately May and August — flightless pups will be trapped and die inside your walls or attic.
Never touch a bat bare-handed under any circumstances — bat bites can be unapparent and rabies is fatal once symptomatic.
Never use poison or lethal control on bats — they are protected species of conservation concern in New Hampshire.
Never use a fan or hit at a bat inside the house — you increase the risk of a bite and stress the animal unnecessarily.
Don't assume a bat isn't rabid because it 'seems fine' — any bat that can be easily approached may be sick per UNH Extension.

Local Context

Bats in New Hampshire homes and attics

The little brown bat (Myotis lucifugus) is NH's most common bat species but is now listed as state-endangered due to white-nose syndrome devastation — 3,230 bats counted at four of the largest NH hibernacula in 2009 crashed to just 16 by 2011. The big brown bat (Eptesicus fuscus) is more resilient and is the species most often seen flying in NH neighborhoods at dusk. Both species favor hot NH attics and barns for maternity colonies in summer.

NH DHHS tracks rabies closely. The bedroom-contact protocol is firm: any bat found in a room where someone was sleeping (or left alone with a child or pet) must be reported immediately to NH DHHS at (603) 271-4496), as bat bites can be unapparent. The bat should be safely captured (using gloves or a container — never bare hands) for rabies testing if possible, but do not risk a bite.

Peak season

Active ~mid-April through October indoors; big brown bats may overwinter in buildings

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Southern New Hampshire

When it's past DIY

When to call a pro for bats in NH

For any bat colony in a NH home, a licensed Wildlife Control Operator (WCO) is the safe, legal path. They know the maternity-season exclusion window, can install one-way bat doors in August, seal every entry point after the colony departs, and handle guano cleanup with appropriate PPE. Anchor Pest Services coordinates with WCOs and can assess the situation, address any ectoparasite (bat bug/mite) concerns after exclusion, and help with prevention.

Signals it's past DIY

When to call a pro

Any bat colony in an attic, barn, or outbuilding — especially if it is May through August (maternity season).
Any bat found in a bedroom or any room with a sleeping person, child, or pet — call NH DHHS (603) 271-4496 AND a wildlife professional.
Any guano accumulation requiring remediation (histoplasmosis risk).
Bat bugs or mites appearing in the home after bats have departed.
Any situation where the maternity-season window, entry-point sealing, and one-way door timing must be coordinated correctly.

Keep them out — prevention

NH-specific

Seal roofline gaps in fall

The safest exclusion window is September through April. Seal every gap 3/8 inch or larger at soffits, gable vents, ridge caps, and around chimneys using galvanized hardware cloth or caulk rated for exterior use.

Cap the chimney

An open chimney is an easy bat roost. Install a chimney cap to block entry while still allowing gas ventilation.

NH-specific

Install a bat house

A properly positioned bat house (south-facing, 15+ ft high, in sun) gives displaced bats an alternative roost and keeps them working on NH's insects.

Not sure it's a little brown bat / big brown bat?

A licensed NH technician can confirm the species and tell you honestly whether it's a DIY fix or a job for a pro — free inspection, same-day service across Southern New Hampshire.

Get a Free Inspection (603) 785-0118

Common Questions

Frequently asked questions

Sources(5)

[1]
NH Fish & Game — Bats in New Hampshire
WNS mortality data, little brown bat state-endangered status, biology
govverified 2026-06-30
[2]
NH Fish & Game — Homeowners and Bats
Maternity-season exclusion restriction, one-way door timing, exclusion protocol
govverified 2026-06-30
[3]
UNH Cooperative Extension — Bats in New Hampshire
Reproductive rate (1 pup/year), 'easily approached bat may be sick' note
extensionverified 2026-06-30
[4]
NH DHHS — Zoonotic Diseases / Rabies
Bedroom bat protocol, NH DHHS contact (603) 271-4496, rabies post-exposure guidance
govverified 2026-06-30
[5]
CDC NIOSH — Histoplasmosis and the Environment
Histoplasmosis risk from bat/bird guano, PPE guidance
govverified 2026-06-30

Written & reviewed by

Verified

Daniel Brady

NH-Licensed Pesticide Applicator · License #782664 (NHDAMF, RSA 430)

Daniel Brady is the New Hampshire–licensed applicator behind Anchor Pest Services, a family-owned pest control company serving the Manchester area since 2017.

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Last updated 2026-06-30

New Hampshire pest control

Dealing with little brown bat / big brown bats in your home?

Anchor Pest Services identifies and handles little brown bat / big brown bat problems across southern and central New Hampshire. Family-owned since 2017, NH license #782664.