2 Types of Bats in Connecticut
Connecticut hosts at least eight bat species, though you are most likely to encounter little brown bats and big brown bats near water and forest edges from May through September. This guide walks you through identifying the common types, finding them in the right habitat at the right time, and understanding what you are seeing when bats emerge at dusk. Start by learning size and forearm length differences, then use seasonal patterns and location clues to narrow down which species you might spot.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated July 2, 2026.
- 7
- species recorded
- August, July, June
- peak months
Verified species, source iNaturalist
2 types of bats recorded in Connecticut
2 bat species have a verified observation record in Connecticut across bats (order Chiroptera), each with at least 10 confirmed sightings. The full list, ranked by how often each is recorded, is below.
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2
Plus 5 more recorded only rarely (fewer than 10 verified sightings). Counts from verified iNaturalist observations. Photos by iNaturalist observers, reused under the licence each observer chose.
Real sighting data, source iNaturalist
236 verified observations on iNaturalist of bat have been recorded in Connecticut, most often in August, July, June.
When bat are recorded in Connecticut
Connecticut hosts at least eight bat species, though you are most likely to encounter little brown bats and big brown bats near water and forest edges from May through September. This guide walks you through identifying the common types, finding them in the right habitat at the right time, and understanding what you are seeing when bats emerge at dusk. Start by learning size and forearm length differences, then use seasonal patterns and location clues to narrow down which species you might spot.
What are the most common bat species in Connecticut?
The little brown bat (Myotis lucifugus) and big brown bat (Eptesicus fuscus) are the two species you will most likely encounter. Little brown bats are smaller, about 3-4 inches long, with glossy brown fur and dark ears. Big brown bats are larger, 4-5 inches, with lighter, coppery fur and broad wings. The tri-colored bat (Perimyotis subflavus) is also present but less common. To separate them, focus on size and forearm length: little brown bats have forearms under 1.5 inches, big brown bats exceed 1.5 inches.
See ourstate wildlife pagefor the next step.
Where in Connecticut are you most likely to see bats?
Bats in Connecticut are most often seen near lakes, ponds, rivers, and wetlands, especially at dusk. State parks like Sleeping Giant, Housatonic Meadows, and the shoreline along Long Island Sound provide good habitat. They also forage around backyard gardens and streetlights if insects are abundant. Start your search near water in areas with mixed open fields and forest edges.
What is the best season and time of day for bat sightings?
The active season runs from May through September, with peak activity in July and August. Bats emerge about 15-30 minutes after sunset and forage for 1-2 hours. Warm, calm nights with low wind offer the best viewing. Avoid cold or rainy evenings as bats stay sheltered. For a reliable sighting, pick a spot near water and arrive at dusk.
See ourstate animal guidefor the next step.
How can you tell bats apart from birds at dusk?
Bats fly erratically with rapid, twisting movements, unlike the smoother, gliding flight of birds. Their wings are thin and translucent, while birds have distinct wing feathers. At dusk, listen for the faint squeaks of echolocation, birds are silent in flight. A bat's silhouette shows a small body with long, narrow wings tapering to a point.
Are there any bat lookalikes in Connecticut?
The only animals easily confused with bats are swallows and nighthawks. Swallows fly during daylight and have forked tails. Nighthawks are active at dusk but have longer, pointed wings with white wing patches. Bats lack a visible tail fork and do not glide as long. Once you focus on wing beat pattern, the difference is clear: bats flutter, nighthawks flap and glide.
What should you do if you find a bat roosting in your yard?
Bats often roost under eaves, in barns, or inside tree hollows. If you find one, do not touch it. Contact a licensed wildlife rehabilitator for advice. To provide a safe viewing opportunity, consider installing a bat house to encourage them to roost away from high-traffic areas. Never disturb hibernating bats in winter, they are vulnerable to disturbance.
Can you photograph bats without special equipment?
Photographing bats requires patience. Use a camera with a fast shutter speed (1/1000 sec or higher) and a telephoto lens. Position yourself near a known foraging spot and shoot just after sunset. High ISO settings help in low light. For cellphone users, try burst mode as bats fly across the sky, it is difficult but possible on bright evenings.
Where can you find bat-themed gear and clothing?
If you want to show your appreciation for bats, Easy Street Markets offers a selection of bat-themed items. Check out the **Cute Bat Sticker** to decorate your gear, or the **Bat Animal Short-Sleeve T-Shirt** for a natural look. For a fun option, the **Baby Bat Cartoon T-Shirt** is a great conversation starter. Browse ourbat t-shirtsfor more designs.
Cute Bat Sticker []() A durable vinyl sticker featuring a charming bat design. Perfect for laptops, water bottles, or your field notebook. Check Price and Availability
Bat Animal Short-Sleeve T-Shirt []() A comfortable tee featuring a realistic bat graphic. Ideal for wildlife outings or casual wear. Check Price and Availability
Baby Bat Cartoon T-Shirt []() You can't go wrong with this Baby Bat, Cute Animal Cartoon Tee Women's -Image by Shutterstock that gives you an authentic style everyday. This T-shirt has been made for your everyday superior comfort. This T-shirt also makes an amazing gift Check Price and Availability
What is the conservation status of Connecticut bats?
The little brown bat and tri-colored bat have suffered severe declines due to white-nose syndrome. Big brown bats are more resilient but still face habitat loss. Connecticut lists the little brown bat as endangered. Supporting bat conservation by protecting roosting sites and reducing pesticide use helps. Learn more aboutbat ecologyand how you can make a difference.
See ourtour planning ideasfor the next step.
What other bat species might I encounter in Connecticut?
Beyond the common three, Connecticut also hosts eastern red bats (Lasiurus borealis), which are reddish and solitary, and northern long-eared bats (Myotis septentrionalis), which are similar to little brown bats but with longer ears. Silver-haired bats (Lasionycteris noctivagans) pass through during migration. Evening bats (Nycticeius humeralis) are rare but may appear in southern coastal areas. Learning these less common species takes practice, but focusing on forearm length, ear shape, and fur color helps you narrow down the identification.
How do bat echolocation and hunting patterns help identify them?
Bats emit high-frequency calls (20-200 kHz) that bounce off insects, allowing them to hunt with precision. Little brown bats produce rapid, repetitive clicks, while big brown bats emit slower, deeper pulses. You cannot hear these directly, but a bat detector converts ultrasonic calls into audible sounds and can tell you which species is hunting nearby. Watching flight patterns also helps: little brown bats make tight, erratic loops, while big brown bats forage in more open, deliberate paths. Combine visual observations with habitat to confirm your sighting.
Gear and field guides
Frequently asked questions
What are the most common bat species in Connecticut?+
The little brown bat (Myotis lucifugus) and big brown bat (Eptesicus fuscus) are the two species you will most likely encounter. Little brown bats are smaller, about 3-4 inches long, with glossy brown fur and dark ears. Big brown bats are larger, 4-5 inches, with lighter, coppery fur and broad wings. The tri-colored bat (Perimyotis subflavus) is also present but less common. To separate them, focus on size and forearm length: little brown bats have forearms under 1.5 inches, big brown bats exceed 1.5 inches. See ourstate wildlife pagefor the next step.
Where in Connecticut are you most likely to see bats?+
Bats in Connecticut are most often seen near lakes, ponds, rivers, and wetlands, especially at dusk. State parks like Sleeping Giant, Housatonic Meadows, and the shoreline along Long Island Sound provide good habitat. They also forage around backyard gardens and streetlights if insects are abundant. Start your search near water in areas with mixed open fields and forest edges.
What is the best season and time of day for bat sightings?+
The active season runs from May through September, with peak activity in July and August. Bats emerge about 15-30 minutes after sunset and forage for 1-2 hours. Warm, calm nights with low wind offer the best viewing. Avoid cold or rainy evenings as bats stay sheltered. For a reliable sighting, pick a spot near water and arrive at dusk. See ourstate animal guidefor the next step.
How can you tell bats apart from birds at dusk?+
Bats fly erratically with rapid, twisting movements, unlike the smoother, gliding flight of birds. Their wings are thin and translucent, while birds have distinct wing feathers. At dusk, listen for the faint squeaks of echolocation, birds are silent in flight. A bat's silhouette shows a small body with long, narrow wings tapering to a point.
Are there any bat lookalikes in Connecticut?+
The only animals easily confused with bats are swallows and nighthawks. Swallows fly during daylight and have forked tails. Nighthawks are active at dusk but have longer, pointed wings with white wing patches. Bats lack a visible tail fork and do not glide as long. Once you focus on wing beat pattern, the difference is clear: bats flutter, nighthawks flap and glide.
What should you do if you find a bat roosting in your yard?+
Bats often roost under eaves, in barns, or inside tree hollows. If you find one, do not touch it. Contact a licensed wildlife rehabilitator for advice. To provide a safe viewing opportunity, consider installing a bat house to encourage them to roost away from high-traffic areas. Never disturb hibernating bats in winter, they are vulnerable to disturbance.
Can you photograph bats without special equipment?+
Photographing bats requires patience. Use a camera with a fast shutter speed (1/1000 sec or higher) and a telephoto lens. Position yourself near a known foraging spot and shoot just after sunset. High ISO settings help in low light. For cellphone users, try burst mode as bats fly across the sky, it is difficult but possible on bright evenings.
Where can you find bat-themed gear and clothing?+
If you want to show your appreciation for bats, Easy Street Markets offers a selection of bat-themed items. Check out the **Cute Bat Sticker** to decorate your gear, or the **Bat Animal Short-Sleeve T-Shirt** for a natural look. For a fun option, the **Baby Bat Cartoon T-Shirt** is a great conversation starter. Browse ourbat t-shirtsfor more designs. ### Cute Bat Sticker []() A durable vinyl sticker featuring a charming bat design. Perfect for laptops, water bottles, or your field notebook. Check Price and Availability ### Bat Animal Short-Sleeve T-Shirt []() A comfortable tee featuring a realistic bat graphic. Ideal for wildlife outings or casual wear. Check Price and Availability ### Baby Bat Cartoon T-Shirt []() You can't go wrong with this Baby Bat, Cute Animal Cartoon Tee Women's -Image by Shutterstock that gives you an authentic style everyday. This T-shirt has been made for your everyday superior comfort. This T-shirt also makes an amazing gift Check Price and Availability
What is the conservation status of Connecticut bats?+
The little brown bat and tri-colored bat have suffered severe declines due to white-nose syndrome. Big brown bats are more resilient but still face habitat loss. Connecticut lists the little brown bat as endangered. Supporting bat conservation by protecting roosting sites and reducing pesticide use helps. Learn more aboutbat ecologyand how you can make a difference. See ourtour planning ideasfor the next step.
What other bat species might I encounter in Connecticut?+
Beyond the common three, Connecticut also hosts eastern red bats (Lasiurus borealis), which are reddish and solitary, and northern long-eared bats (Myotis septentrionalis), which are similar to little brown bats but with longer ears. Silver-haired bats (Lasionycteris noctivagans) pass through during migration. Evening bats (Nycticeius humeralis) are rare but may appear in southern coastal areas. Learning these less common species takes practice, but focusing on forearm length, ear shape, and fur color helps you narrow down the identification.
How do bat echolocation and hunting patterns help identify them?+
Bats emit high-frequency calls (20-200 kHz) that bounce off insects, allowing them to hunt with precision. Little brown bats produce rapid, repetitive clicks, while big brown bats emit slower, deeper pulses. You cannot hear these directly, but a bat detector converts ultrasonic calls into audible sounds and can tell you which species is hunting nearby. Watching flight patterns also helps: little brown bats make tight, erratic loops, while big brown bats forage in more open, deliberate paths. Combine visual observations with habitat to confirm your sighting.
Keep exploring
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