4 Types of Bats in Iowa

1. What are the most common bats in Iowa?

The big brown bat (Eptesicus fuscus) and little brown bat (Myotis lucifugus) are the two species you are most likely to see. Big brown bats have a wingspan of about 13 to 16 inches and glossy brown fur. Little brown bats are smaller with a wingspan of 8 to 10 inches and darker, often blackish-brown fur. The eastern red bat (Lasiurus borealis) and hoary bat (Lasiurus cinereus) are also present but less frequently encountered. Other Iowa species include the silver-haired bat, tri-colored bat, pallid bat, and evening bat, though these are either rarer, seasonal, or found only in limited parts of the state.

2. How can you identify a bat by its size and shape?

Size is the easiest starting point. Big brown bats have a forearm length of about 1.6 to 2 inches, while little brown bats have a forearm under 1.5 inches. Look at the fur: big browns have a uniform brown color, little browns often have a slight golden sheen. Eastern red bats are medium-sized with reddish-orange fur and a distinctive white shoulder patch. Hoary bats are large with frosted, grayish fur and a wingspan up to 16 inches. Silver-haired bats have dark fur with white-tipped hairs giving a frosted appearance, while tri-colored bats show a tri-colored pattern with dark underparts and lighter-tipped fur.

3. Where are the best places to see bats in Iowa?

Your best odds are near standing water such as ponds, lakes, or slow-moving rivers at dusk. State parks likeMaquoketa Caves State Parkand Ledges State Park have good bat activity. Caves and abandoned buildings may host maternity colonies, but you should never enter a cave without permission. Backyards with flower gardens also attract insects and therefore bats.

See ourstate animal guidefor the next step.

4. When is the best time of year to spot bats in Iowa?

Bats are most active from mid-May through early September. They emerge from hibernation in April and begin migrating or entering torpor by October. The peak for sightings is June and July when pups are learning to fly. Evening emergence starts about 15 to 30 minutes after sunset. Little brown and big brown bats tend to hibernate locally in caves and mines, while eastern red and hoary bats are migratory, moving through Iowa during spring and fall.

5. What are some lookalike species and how to tell them apart?

The evening bat (Nycticeius humeralis) looks very similar to the little brown bat but has a slightly broader tragus and darker face. Big brown bats can be confused with the hoary bat at a quick glance, but hoary bats have much longer wing tips and distinctly frosty fur. If you see a bat with reddish fur in a tree, it is almost certainly an eastern red bat. Silver-haired bats may be mistaken for hoary bats, but silver-haired bats have solid dark ears while hoary bats have fur-trimmed ears. Tri-colored bats are smaller than little browns and show a clear three-part fur coloration.

6. How do bat echolocation calls help with identification?

Using a bat detector is a reliable way to identify species in flight. Big brown bats call at lower frequencies (25-30 kHz), while little browns call higher (40-50 kHz). Eastern red bats have a distinctive descending call pattern. Without a detector, focus on visual clues like size, flight style, and habitat. Bats flying in tight circles over water are often little browns. Hoary bats and silver-haired bats typically fly at higher altitudes and may produce audible clicks. Hobbyists can purchase affordable bat detectors online or use smartphone apps, though these apps are less accurate than dedicated hardware.

7. What should you do if you find a bat in your house?

Do not touch the bat with bare hands. Open a window or door and close off the room to allow it to escape on its own. If it stays, contact a licensed wildlife rehabilitator. Never try to catch it by hand because bats can carry rabies. For more on bat behavior, check ourbat species hub. Most bats that enter homes are accidental visitors seeking shelter or water, not aggressive. A simple open door usually solves the problem within minutes.

8. Which Iowa bats are listed as threatened or endangered?

The tri-colored bat (formerly eastern pipistrelle) has declined sharply across North America due to white-nose syndrome, a fungal disease that affects hibernating bats. In Iowa, tri-colored bats are much rarer than they were 20 years ago. The little brown bat population has also suffered significant losses from the same disease, though they remain more common than tri-colored bats. The pallid bat is considered state-endangered and is found only in limited southwestern Iowa counties. When you see any of these species, photograph or report your sighting to the Iowa Department of Natural Resources to help track population trends. Healthy bat populations need healthy cave ecosystems, so cave conservation matters.

9. What is white-nose syndrome and why does it matter?

White-nose syndrome is a fungal infection caused by Pseudogymnoascus destructans that kills hibernating bats during winter. The fungus grows on a bat's nose, wings, and skin, disrupting their hibernation and draining their energy reserves until they starve. Since its discovery in 2006, it has killed millions of bats across North America. Iowa's tri-colored bats have been hit hardest, with some colonies declining by 95 percent or more. Little brown bats, once the most abundant species, have also experienced major population reductions. The disease spreads from cave to cave when people enter caves and contaminate their gear and clothing. Proper cave etiquette and gear decontamination are critical tools for slowing the spread. Scientists are working on treatments and vaccines, but prevention through cave conservation remains the strongest defense.

10. Where can you find bat-themed gear and shirts to show your interest?

If you want to wear your enthusiasm for bats, Easy Street Markets has a selection of bat t-shirts and stickers that make great conversation starters. Here are a couple of top picks:

Cute Bat Sticker

This durable sticker shows a friendly bat design perfect for laptops or water bottles.Check Price and Availability

Bat Animal Short-Sleeve T-Shirt

A crisp, simple bat silhouette on a soft tee. Great for casual birding or bat walks.Check Price and Availability

Baby Bat Cartoon T-Shirt

You can't go wrong with this cute cartoon bat tee. It makes an amazing gift for anyone who loves bats.Check Price and Availability

Browse more bat apparel on ourbat t-shirts page.

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