Public Health Concerns
Bats, like many other mammals, can contract and spread rabies through a bite. However, according to studies, less that one half of one percent of bats actually carries rabies and even those rarely become aggressive. To avoid problems, never attempt to handle a bat barehanded. Like any animal, it may bite if injured or frightened.
According to the Center for Disease Control, people cannot get rabies from just seeing a bat in an attic, in a cave or at a distance. In addition, people cannot get rabies from having contact with bat guano (feces), blood, or urine or from touching a bat on its fur (even though bats should never be handled).
If you are bitten by a bat, or if saliva from a bat gets into your eyes, nose, mouth, or a fresh wound, seek medical attention immediately. Whenever possible, the bat should be captured and sent to a laboratory for testing. In addition, bats that are found in a room with a person who cannot reliably rule out physical contact (for example a sleeping person, a child, a mentally disabled person or an intoxicated person) will need to be tested for rabies. If contact has occurred or is suspected call your personal physician or local health department immediately.
What To Do With A Bat Found Outdoors
Foliage-roosting bats have beautiful fur in shades of reds, yellows and tans (like dried leaves), or they have multi-colored fur that is frosted with white. These bats are frequently found on the ground in the early summer when mothers are moving their young, or when they become grounded following blue-jay attacks or storms. Occasionally, these bats panic and defend themselves when humans approach by spreading their wings in mock-attack and making loud hissing or clicking noises. Follow the steps given below to rescue a tree-roosting bat. If you feel unequipped to move the bat, proceed to step five. Note: If the bat is a gray or brown color, it is probably a crevice-dwelling species. Crevice-dwelling bats found out of doors and grounded will need to be examined and cared for by a wildlife rehabilitator. Place the bat into a container using the method described in “How To Remove A Bat Found Indoors”, and contact a local wildlife rehabilitator for assistance.
1. Make sure the bat is safe from predators. Have someone stand guard over the bat so it does not fall prey to domestic pets, blue jays etc. If the bat remains quiet and still, proceed to step 2. If the bat panics as described above, contact a local wildlife rehabilitator for assistance..
2. Do not use your hands to help the bat. Instead, gently touch a small tree branch (two or three feet in length) to the bats feet. This usually initiates a grab reflex and the bat will grip the branch with its toes. When you lift the branch you can inspect the bat (or mother bat with babies) for any injuries. If the infants are clinging to the mother and there are no apparent injuries, proceed with step 3. If injuries are detected, contact a local wildlife rehabilitator for assistance.
3. SLOWLY move the bats into the branches of a nearby tree. This must be done very carefully. A sudden move may cause a mother bat to fly off and abandon her young. Using a ladder, gently secure the branch into a spot where foliage and leaves conceal the bats. The spot should be on a branch at least eight or more feet from the ground, with a clearing below to enable the bat to take flight. (Do not place the bats in the same tree where the attack may have occurred and do not place bats on the trunk of a tree where they will be vulnerable to predators. Also make sure there is no visible bird’s nest in the tree.) Proceed to step 4.
4. Monitor the area. Check the area the following morning. If the bat has remained in the same position overnight it may have an undetected injury or illness. If the mother bat is gone but her babies remain, the babies may have been abandoned.
How To Remove A Bat Found Indoors
A bat that is found indoors is most likely to be a crevice-dwelling species. Although the fur color of crevice-dwelling bats varies, it is usually a shade of gray or brown. These bats are often lost youngsters or migrating bats. Oftentimes they will find their way out through an open window or door. If a bat is flying in a room you can help it find its way out through an open door by turning off the lights inside the room and shining a flashlight beam out the open door. Make sure doors to other rooms are closed off first and the only door open leads to the outside. If this is not an option, and if you feel confident that you can move the animal without physically touching it or injuring it, proceed to step one.
1. Wait until the animal is motionless. A bat that is flying is almost impossible to catch, and you have a greater chance of injuring the bat if you attempt to capture it while it is airborne. In addition, bats that are caught while flying frequently panic and attempt to bite. Be patient. Wait until the bat lands and is still, and then proceed to step 2.
2. Contain the bat. Quietly approach the bat, and wearing thick gloves or using a thick towel, gather the bat up (holding it securely but not tightly) and place it into a box or similar container with a lid. Or instead, simply place a box, waste can, coffee can or similar object over the bat where it has landed. Then, take a piece of cardboard and gently slide it between the box and the surface the bat is on (i.e. floor, wall or ceiling). Keeping the cardboard in place, gently turn the container right side up. If the bat is captured during the day proceed to step 5. If the bat is captured at night and does not appear to be a baby bat, proceed to step 3. Important note!: Do not place the bat in a bird cage or container with small openings. Bats are very intelligent and can easily squeeze through a 1/4 x 1/2 inch crack.
3. Release the bat outdoors at nightfall. Once the bat has been captured, take the container outdoors. Take a flashlight and a towel or gloves with you in case the bat has problems flying away. Find an elevated area (such as a deck or ladder), lift the box over your head, and tilt it to the side so the bat can fly out (the bat will not be able to fly out of a grounded container in a vertical position). Proceed to step 4. (Note: Do not release the bat during the day or during cold or bad weather. Instead, proceed to step 5).
4. Watch it leave. Use the flashlight to watch the bat fly away. If the bat does not fly away, or attempts to fly but seems unable to, it is likely that is has an injury or illness. It may be a disoriented juvenile, or it may simply be dehydrated or starved from being trapped indoors. If this is the case, use the towel or gloves (not bare hands) to gather the bat up. Keep the bat in the closed container and put it in a safe place that is free of children, pets, or other hazards.
How To Remove Bats From An Attic Or Building
The presence of bats in an attic or building does not necessarily constitute a health hazard. In fact, a bat roost increases property values in China, as they are thought to bring good luck and happiness! If the colony is small, it is usually wisest to leave it undisturbed and enjoy the free reduction in mosquitoes.
While bats are beneficial animals, relocating bats safely and humanely helps to maintain bat populations and decreases the chances that bats and people will come in contact with each other.
Where bats enter and roost in buildings
Bats may roost in attics, soffits, louvers, chimneys, under siding, eaves, roof tiles or shingles and behind shutters (see diagram). In sports stadiums and parking garages, bats sometimes roost in expansion joints between concrete beams. They can enter through openings as small as one-half inch in diameter (1.3 cm). Common points of entry include open windows or doors, broken or poorly-fitted screens, loose or missing shingles or tiles, places where flashing or boards have come loose and locations where pipes or wiring enter buildings. Openings often occur where walls meet the eaves at the gable ends of an attic, where porches attach to the main part of a house, or where dormers meet the roof. Other points of entry are associated with siding. For example, cracks and crevices are often created where siding forms corners, or at places where it meets windows, doors or chimneys (see diagram). Bats can sometimes be detected by the presence of black or brown stains from body oils or droppings around cracks or crevices formed by ill-fitting building materials. Bat droppings may also appear on walls, under porches or decks, or on floors beneath dilapidated ceilings. Bat droppings are dark and do not contain any white material. Although they may resemble small hard rodent pellets, bat droppings are soft and easily crushed, revealing shiny insect parts.
Basic steps for bat exclusions
1. Conduct exclusions only during the months of April-May and August-September. Summer exclusions may cause baby bats to become trapped in your home and separated from their mothers. Winter exclusions could trap hibernating bats in the building.
2. Install a bat house near your home so the bats will have a new place to move into after you have done the exclusion.
3. Identify where bats are entering and exiting your home by watching from sunset to 60 minutes after sunset.
4. During the day, cover the openings with screen or plastic mesh. Attach the screen or mesh on the top and sides, leaving the bottom open allowing the bats to exit. They won’t be able to get back in and will have to look elsewhere for a new roost.
5. Leave the screen or mesh in place for 10 days to make sure all of the bats have left your house. Check to make sure they have not found a new way into your house by watching at sunset. Once all bats have vacated, permanently seal the openings.
Providing a safe exit for bats
There is little reason to evict bats from buildings where they are not causing a nuisance. However, bats should be prevented from entering human living quarters. This can be accomplished by inspecting the inside of a building for small openings through which bats could enter. All openings connecting the attic or other roosting areas to inside living quarters should be sealed, although entry points on the outside of the building should be left open, allowing bats to exit. Draft-guards should be placed beneath doors to attics; electrical and plumbing holes should be filled with steel wool, caulking or weather-stripping. Bats have small teeth for eating insects; they do not gnaw through wood or other building materials like rodents. Caulking, flashing, screening or insulation can be used to seal most openings on the inside. Expanding urethane foam products should not be used to seal cracks where bats are active, because they can become caught in it. Caulk should also be applied early in the day so that it has time to dry before bats emerge in the evening.
In some instances, noise or odors from large colonies of bats can become a nuisance. When bats must be evicted from a building, netting or tubes that function as one-way valves must be placed over the openings bats use to enter and exit. These one-way valves allow bats to leave, but not reenter the building. Valves may be constructed from lightweight plastic netting (1/6 inch-0.4 cm-or smaller mesh), or plastic pipes or tubes. These exclusion devices should be left in place for 10 days to ensure all bats have exited. It is not appropriate simply to wait for bats to fly out at night and then seal openings. Not all of the bats leave at the same time, and some bats may remain inside all night. Take weather conditions into consideration when deciding how long to leave the netting or tubes in place; there may be evenings (such as during storms), when no bats exit.
Bats often roost in buildings seasonally, including during maternity periods, and exclusions should not take place until young bats are able to fly. After the young are old enough to fly, all bats can be excluded. The maternity season begins as early as mid-April in the southernmost U.S., midJune in the northern U.S. and Canada. Young bats are flying and exclusions can resume by late August. In late fall most house-dwellings bats either migrate to warmer climates or enter caves or abandoned mines to hibernate. However, a few species can hibernate in buildings, and in the mildest climates, they may even remain active year-round. If bats are present in cold regions during the winter, exclusions should be postponed until spring when they emerge to feed.
Exclusion is the ONLY effective solution for permanently removing bats from buildings. Trapping and relocating is ineffective since bats have excellent homing instincts and simply return, even when released at great distances. The use of pesticides against bats is illegal and counterproductive. Poisoning greatly increases the likelihood of bats coming into contact with people and pets. Naphthalene, the active ingredient in moth balls, and ultrasonic devices are often promoted as bat repellents. However, ultrasonic devices are ineffective against bats, and to be effective, naphthalene must be used in such large quantities that it poses a significant health hazard to humans.
Using netting to exclude bats
Bats sometimes enter buildings through openings on smooth surfaces of exterior walls or through louvers. In such cases, plastic or lightweight, flexible netting with 1/6 inch (0.4 cm) mesh or smaller, should be secured to the building along the top and sides of the opening as shown in the diagram. It should extend 18 to 24 inches (46 to 61 cm) below the bottom edge of the opening and should remain in place for a minimum of 30 days to ensure all bats have exited. Then, openings should be permanently sealed with silicone caulking, caulk backing rod, hardware cloth, or heavy-duty netting. In some cases, sealing may require repair or replacement of old, deteriorated wood. When bats are using multiple openings to exit and enter, exclusion material should be placed on each opening unless it can be determined with certainty that all areas used by the bats are connected. If so, some openings can be sealed as described above, and netting can be placed over the openings used by the most bats. Even when all roosting areas are connected, bats will sometimes refuse to use alternative exits. In this case, exclusion material must be installed over all exits. After this has been done, watch to make sure the bats are able to exit safely. If they do not appear to be exiting, or appear to be having trouble doing so, make adjustments or add new valves as needed.
Using PVC pipe or empty caulking tubes to exclude bats
There are a number of situations in which tubes work best as bat exclusion devices. Examples include openings used by bats on buildings constructed from materials that do not create smooth exterior walls, such as those found on brick or stone houses, and log cabins. Tubes also work best for holes located at corners where walls meet and on horizontal surfaces such as soffits. Exclusion tubes should have a 2-inch (5 cm) diameter and be approximately 10 inches (25.4 cm) in length. Exclusion devices can be made from PVC pipe or flexible plastic tubing. According to Laura Finn of Fly by Night, Inc., empty caulking tubes work well for this purpose. When using caulking tubes, both ends must be cut out. Use of a flexible plastic tube makes it easy to either squeeze one end of the tube so that it fits into a crevice, or cut one end of the tube into flaps that can be fit over an opening and stapled, nailed, or taped to the building (see diagram). Bats are unable to cling to the smooth surface of these tubes. Do not let the tube project more than 1/4-inch (6 mm) into the opening, ensuring that bats can easily enter the tube to exit. Caulking tubes must be thoroughly cleaned before use to prevent bats from sticking to wet caulk and because dried caulk creates a roughened surface, making it possible for bats to re-enter. Once the tube has been inserted over the hole, a piece of light weight, clear plastic can be taped around the end of the tube that projects to the outside (see diagram) to further reduce the likelihood of bats reentering, though this is typically not necessary.
Plastic sleeves collapse on themselves, preventing bats from reentering once they have crawled out through the tube. After the tube has been inserted into or over the opening used by bats, any spaces between the outer rim of the tube and the building must be sealed shut. Be sure also to seal shut any other openings in the building that bats could use to reenter. Leave the tube in place for a minimum of 30 days to ensure all bats have exited. After the bats have been excluded, the tube should be removed and the opening permanently sealed.
Some concrete parking garages have lengthy crevices used by bats. Multiple exclusion tubes will need to be placed every few feet along the length of each crevice; spaces between the tubes should be closed with heavy-weight (1/6 inch mesh) netting (see diagram). Fold the netting so that it fits into the crevice, and caulk it in place as shown in the diagram. The same procedure can be used in lengthy crevices created where flashing has pulled away from a wall.
Plastic tubes also work best for excluding bats from under Spanish (clay) or concrete roofing tile. Bats typically enter through open ends of the tiles on the lowest row, or through openings created where tiles overlap one another. Observe the building when bats fly out in the evening to determine which openings they use. Exclusion tubes should be placed in these openings (see diagram). Multiple exclusion tubes are often needed to exclude bats from problem roofs. Collapsible plastic sleeves should also be attached to the ends of the tubes. Heavy weight netting can be folded and inserted into openings where tiles overlap (see diagram).
Tiles are sometimes temporarily removed to replace a layer of tar paper. When this is done, a layer of coarse fiberglass batting can be put over the tar paper and under the tiles. Constantine (1979) found that the fiberglass layer repelled bats, although he recommended against use of batting within 6 inches (15 cm) of open tile ends to prevent birds from pulling it out for nesting material.
Bats may also enter a building through spaces beneath corrugated or galvanized roofing sheets. These roofs can be sealed with a variety of materials such as caulk backing rod during months when bats are not present, or after they have been excluded from a building by use of exclusion tubes.
Special modifications may be needed when bats roost in chimneys or in separations between chimneys and roofs. If bats are roosting inside the chimney, construct a wire cage from 1/4-inch hardware cloth lined with window screen. A section of PVC pipe can be cut and then inserted through holes cut into the sides of the wire cage (see diagram). Although bats are able to simply drop down and out of a vertically placed tube that extends below the roost, they are not able to grip the slick surface to crawl out if the tube extends upward above the roost. Therefore, the tubes should project horizontally or down. A collapsible plastic sleeve should be placed over the ends of all exclusion tubes used on chimneys. Once the bats have been excluded, a chimney cap should be installed.
Need help with a bat exclusion
If you are not able to do a bat exclusion on your own, professional help is available. Be sure to ask your local provider to follow humane methods for removal including:
- Install a bat house nearby prior to the exclusion
- Do not perform an exclusion between May and August
- Create a one-way door allowing bats to exit rather than applying chemicals or pesticides inside the home
- Many bats are currently being studied and may be recommended for protection under the Endangered Species Act. For current legal status and other information, contact your local wildlife office.
All species of bats are classified as protected wildlife and cannot be hunted, trapped, or killed (WAC 232-12-011). The Department of Fish and Wildlife makes exceptions for bats found in or immediately adjacent to a dwelling or other occupied building. In such cases, these animals may legally be removed and no permit is necessary (WAC 232-12-011).
Transporting And Handling
Useful Items – light leather gloves, handkerchief, towel, cloth, and cardboard box.
- Cardboard box
Line box with cloth
Drape cloth over one side of the container so the bat can cling on vertically during transit
Ventilation holes in box
Avoid direct sunlight – danger of overheating
- All bats can potentially bite – always wear gloves or use cloth to lift bat to prevent being nipped.
Always gently detach bat’s claws from surface before lifting.
Handle extremely gently by laying bat across your fingers and restraining the body gently with your thumb.
Take care not to strain the forearms and flight muscles.
Do not try to calm it by talking to it.
If flapping excitedly, cover with light cloth to calm and restrain.
Short Term Temporary Adult Bat Care
- Do not mix species
Bat will climb out of container if not fully enclosed
Aquarium must have fine mesh lid for ventilation, box must have holes
Line bottom of container with cloth or kitchen towel
Line walls with cardboard to darken the interior
Drape cloth or kitchen towel over side of container for bat to cling on to
House in quiet, warm, dark area, away from domestic animals
- Fish aquarium
Sturdy cardboard box
Plastic pet transportation box
- An electric heating pad can be placed under part of the cardboard box
Or an electric heating pad wrapped in a towel can be placed inside the container, at one end
The bat needs to be warmed so it feels warm to the touch
Beware overheating can also kill so give enough space that the bat can crawl away from the heat if necessary
If the bat is cold it will be unwilling to feed
- When bat warmed and alert, offer:
Tap water or rehydration solution for bat to lick from artist’s paintbrush
Rehydration solution – “1 pinch of sugar and 1 pinch of salt in 1 cup of warm water”
If bat bright and alert, leave milk bottle top/jam jar lid with a few drops of each of these fluids in container
- Artist’s paintbrush
Canned Cat or dog food, especially the jelly part, mashed into a fine paste.
Offer to the bat to lick from the tip of an artist’s paintbrush or eye dropper
Frequency and Quantity:
- Quantity depends on time of year and size/age of bat but roughly 2-8g of food per day
An orphaned, un-weaned neonate/juvenile may need to be fed every 2 hours
An adult bat can be fed once after dark
Leave tiny amount of food in bottle top in container but hand feeding will be necessary initially
Short Term Temporary Baby Bat (Pup) Care
Same as for adult bat, see above
Same as for adult bat, see above
These emergency feeding instructions are only good for the 24-hour period it might take you to get the orphan to a licensed rehabilitator.
- Artist’s paintbrush
Rehydration solution and milk suggestions:
Milk formula – 3.5 ounces (100ml) of canned Meyenberg evaporated goats milk mixed with 2 scoops (8.6g each) Similac® Go & Grow, Soy-Based Powder reconstituted as prescribed by the manufactures directions using filtered water.
Another alternative for a temporary milk formula is Canin Baby Dog Formula reconstituted as prescribed by the manufacture directions using filtered water.
Note: A 24 hour feeding of rehydration solution is fine if milk replacement is difficult to obtain.
Rehydration solution – “1 pinch of sugar and 1 pinch of salt in 1 cup of warm water”
All feeds should be lukewarm
Allow to rest between feeds, only handle for feeding
WARNING – Never put a pup away with milk on its face or body. Doing so will result in eye infections and/or skin infections that may result in death.
DANGER – Aspiration Pneumonia – inhaling fluid into the lungs
If a bubble of liquid appears at the nose or the pup starts sneezing or shaking its head, stop feeding immediately and tilt the head down to allow any fluid to drain out. Dab with tissue, take a break, and then start again very slowly
- Use rehydration solution for the first few feeds while you and the pup get used to feeding
Hold the pup on its belly with its head slightly lowered whilst feeding
Always feed patiently, slowly and gently
Try to get the pup to lick/suck the fluids slowly rather than guzzling
Take to vet for antibiotics and other respiratory drugs if pup inhales fluids and starts coughing for any long period of time, breathing heavily or breathing with mouth open
- In general offer as much as they will take, they will stop when they’re full.
Never feed an animal so much fluid that its tummy becomes hard and distended.
- If pup has no fur, feed 8 times per day
A fully furred pup can be fed 4 times per day
If they are unwilling to wake up and feed, extend the gap between feeds by ½ hour
- Rinse all utensils before each feeding.
After use, dismantle feeding equipment and clean thoroughly in warm soapy water, rinse, then place in a bowl of sterilizing solution.
Stimulate to initiate urination and defecation:
Tree bat pups need to be stimulated to initiate urination and defecation. Cotton swabs are too rough for this purpose. Instead, use a the corner of a gauze pad that has been dipped in warm water to gently flick the pup’s anus and genitals. Use only the corner to softly flick the area. Flick repeatedly until the pup urinates or defecates. While newborn tree bats require stimulation, most of the crevice species do not.
Additional Information About Bats: