Bat Identification in Central Florida: How to Tell Which Species Is in Your Attic

Reviewed by Steve DeMoor (“Dr. Critter”), Florida wildlife control professional since 1996.

If you have bats in your Central Florida attic, the first useful question isn’t “how do I get rid of them” — it’s “what species is in there.” Species matters because it tells you the colony size, the entry-point geometry to look for, and the legal timing of any exclusion under Florida Administrative Code 68A-9.012. Below is a field guide to the three bat species we encounter most often in Orlando, Sanford, Lake Mary, Casselberry, Winter Park, Windermere, Palm Bay, Daytona Beach, and the rest of the Central Florida service area.

How to Use This Guide

You almost never get a good look at a bat in an attic. Instead, identification comes from a combination of: (1) emergence behavior at dusk, (2) the size and shape of the guano, (3) entry-point geometry, and (4) staining patterns at the entry. Get any two of these right and the species is usually clear.

Brazilian Free-Tailed Bat (Tadarida brasiliensis)

This is the bat in your Central Florida attic about 70% of the time. Free-Tailed Bats are colony animals and the most common attic species in the entire Southeast.

• Size: Body 3.5–4 inches long, wingspan around 12 inches.
• Color: Dark brown to grayish brown with short, velvety fur.
• Identifying feature: The tail extends roughly half an inch past the tail membrane — hence “free-tailed.” In flight you cannot see this, but if a bat is grounded it is diagnostic.
• Flight: Fast, narrow-winged, direct. Free-Tailed Bats fly higher and straighter than the other Central Florida species — they often look more like swifts than like fluttering bats.
• Colony size in attics: Often 50 to several hundred animals. Large colonies leave 6+ inch piles of guano under the primary roost.
• Common entry points: Soffit gaps, roof-line junctions where two pitches meet, ridge vents without exclusion mesh, lifted dormer flashing. They will use any gap of 3/8 inch or larger.
• Guano: Dark brown to black, dry, crumbly, with a faint metallic sheen when crushed (undigested insect chitin).

Evening Bat (Nycticeius humeralis)

The second most common Central Florida attic species — typically smaller colonies than Free-Tailed, more often found in detached structures.

• Size: Body 3–3.5 inches, wingspan around 10 inches. Smaller than Free-Tailed.
• Color: Uniform chocolate brown with slightly paler underparts.
• Identifying feature: Short rounded ears, blunt tragus (the small projection inside the ear). The tail is fully enclosed in the membrane — no free tip.
• Flight: Slower, more fluttery, swooping flight pattern. Often seen feeding low over yards and pools.
• Colony size in attics: Usually 10–50 animals.
• Common entry points: Gable louver gaps, fascia gaps, lifted shingles, gaps where flashing meets a chimney.
• Guano: Similar to Free-Tailed but typically smaller piles because the colonies are smaller.

Little Brown Bat (Myotis lucifugus)

Less common in Florida than the two above but does appear in older barns, unsealed attics, and historic structures. White-nose syndrome has reduced populations across the East Coast, so finding a Little Brown roost in Florida is increasingly notable — and worth documenting through FWC if you have one.

• Size: Body 3–3.5 inches, wingspan 9–11 inches.
• Color: Glossy brown with a coppery sheen on the back, paler buff underparts.
• Identifying feature: Long, pointed ears with a long, narrow tragus. The fur looks polished compared with the duller Evening Bat.
• Flight: Quick, erratic, with sharp directional changes. Often feeds over water at dusk.
• Common entry points: Old barn cupolas, gaps around historic-construction roof junctions, vents in older homes.

How to Tell If You Have Bats (Not Rats, Squirrels, or Birds)

Once you have a candidate species in mind, confirm that what you have is actually bats:

• Timing: Bats leave the roost at dusk and return before dawn. Daytime activity is rats or squirrels.
• Emergence: Watch the roof line at sunset in summer. Bats exit one by one in a steady stream over 15–30 minutes.
• Staining: Dark brown or black smears where bats squeeze through — body oils stain the surface over time.
• Sound: Bats are nearly silent except for a faint chittering at dusk. Loud thumps and scurrying are not bats.
• Guano vs. rat droppings: Bat guano crushes to a fine powder with sparkly insect parts. Rat droppings stay firm and rounded.

What to Do Once You’ve Identified the Species

Whatever the species, the next steps are the same in Florida:

1. Confirm the colony with an evening emergence count.
2. Check the calendar — exclusion is illegal from April 16 to August 14 (FAC 68A-9.012). FWC bat conservation guidelines.
3. Document every active entry point of 3/8 inch or larger.
4. Schedule a one-way exclusion outside the maternity window.
5. Plan for guano remediation — accumulated guano carries Histoplasma capsulatum.

For a step-by-step walkthrough of the legal exclusion process, read our guide to removing bats from a Florida attic.

When to Call Dr. Critter

If you think you have bats but cannot pin down the species or the entry points, that’s a good moment to have a professional do an evening emergence count. Schedule a free bat inspection or call 800-932-7287. We will identify the species, map the active entries, and put together a legal exclusion plan timed for the open window.